This PDF file contains the front matter associated with SPIE proceedings Volume STCE22 including the Title Page, Copyright information, Table of Contents, and Conference Committee Page.

There is a certain view that port planning and construction will cause impact on the marine hydrodynamics and environment to some extent. Two breakwaters and some high-piled wharfs are planning in Dongjiakou Port area of Qingdao Port. Taking the case as an example, the paper established the hydrodynamic model and water environment model to research the impact of breakwaters and wharfs planning and construction on marine dynamics and environment. Simulation results demonstrate that the currents velocity are no longer changing from a distance of 2 kilometers away. The tidal volume is decreasing about 0.07% after the planning implementation. The suspended sediment caused by port construction has an adverse impact on water quality of surrounding waters. The conclusion can benefit for port planning and construction.

Due to the excessive travel volume in urban rail transit operations and the mismatch between supply and demand, it is necessary to restrict the passenger flow of some stations, so that the passenger flow can match the station capacity. Therefore, based on the barrel principle, this study takes the station as the key observation point, divides the service level into different levels, and judges whether the passenger flow control measures are triggered. Finally, we use the simulation software MassMotion to build the Longze Station model for case study. The results show that the adoption of passenger flow control measures has a significant impact on improving the service level of the station, effectively reducing the number of people gathered on the platform and the passenger flow density in the bottleneck area.

In this paper, 36 common tram signal priority control scenarios were established based on the traffic network form, background traffic flow, tram line form, and signal control mode. Based on the summary of engineering practice, an evaluation index system of tram signal priority effect was designed for the tram, social vehicles, and the overall situation of intersections. A microscopic traffic simulation model was constructed for different scenarios, and the evaluation and analysis were carried out.

This paper takes the future scale of Hainan yacht industry as the research object, based on the data on the current scale of the Hainan yacht industry, combined with the development trend under the background of the construction of Hainan Free Trade Port. This paper uses trend extrapolation method to predict market scale, seagoing scale, and berth scale in Hainan yacht industry, and uses the scale prediction results to put forward relevant suggestions such as strengthening infrastructure construction, product development, and policy support.

One-way carsharing is a new urban transport alternative allowing members to use the car from a fleet of vehicles for short periods. In carsharing system, the imbalanced vehicle distribution at stations by dynamic demands is a general problem, lowering the efficiency of the system. To evaluate the performance of carsharing system, this paper focuses on the opportunity loss of vehicle inventories at stations. A service level KPI is established to observe the full-car status, no-car status and no-battery status separately on stations. By conducting a real case study in Toyota, the result shows that the service level in different time periods at a station-level and cluster level. It shows that no-car status is the primary opportunity loss existing in Ha:mo carsharing system. Based on the clustering analysis of opportunity loss status, different suggestions are given to reduce the probability of potential demand in a cluster level. The result also provides a good basis for further system planning and deployment.

In order to improve the vehicle loading rate in the logistics and distribution process, this paper studies the vehicle routing problem with time window and simultaneous delivery and pickup under fuzzy demand. Triangle fuzzy numbers are introduced to describe the uncertainty of customer demand and construct a multi-objective function model with the goal of minimum total cost. Genetic algorithm (GA) is used to solve this problem. Compared with the simple delivery scheme and simple pickup scheme, the results show that the designed model and algorithm optimize the vehicle path and significantly reduce the number of vehicles, improve the average vehicle load rate and reduce the enterprise cost.

To verify the accuracy of the lane change safety model, a vehicle with an automatic lane change function was used as the test platform to conduct the test on public road. Data during the lane change process were collected with different subjects as the test samples. The takeover action of the subject served as the basis for the subjective determination of lane change safety, thus validating the effect of different lane change safety models, mainly the vehicle behind the target lane, on lane change safety. The results show that the method works for evaluating the safety performance of lane change of a self-driving system and provides a methodological basis for testing and evaluating the lane change function of self-driving.

The transportation industry is one of the major sectors that produce greenhouse gas emissions. In order to promote the low-carbon process of the transportation industry, based on the differentiated charging of expressways, this paper constructs a carbon emission calculation model and a carbon pricing model from the perspective of carbon emission reduction income, and analyzes the carbon emissions under different charging rates of expressways and the economic benefits of carbon emission reduction. On this basis, the comprehensive income of the high-speed group is composed of two parts: toll income and economic by carbon emission reduction. Considering the benefits of carbon emission reduction, the formulation of highway toll rates can bring more environmental benefits under the condition of ensuring the actual economic benefits of the high-speed group. The results show that when the toll rate is 2.0 yuan/km, the high-speed group can obtain the optimal carbon emission reduction benefits and toll benefits. This study can promote the low-carbon process of the transportation industry and provide a reference for the amount and method of government subsidies to the transportation sector.

Most of the traditional traffic accidents are caused by human factors. Among them, overspeed driving is one of the main causes of serious traffic accidents. Based on the analysis of CIDAS accident data, this paper counted the speed limit of the road section when the speeding accident occurred, and elaborated the test scenarios and test methods of the speed limit information function and speed limit warning function of the speed assist system in the 2021 version of C-NCAP. At the same time, the limitations of the traditional speed limit warning system are analyzed, and the technical route and solution of the current speed assist system for passenger cars are introduced. Finally, three representative models are selected to verify the test scheme, and the test results are simply analyzed.

In order to grasp the actual congestion level, travel safety and improve the management level of urban rail transit station, and study the analysis method of platform passenger congestion, this paper uses video technology to obtain the location distribution of passengers at Xi’dan station of Beijing Metro, and studies the distribution process and law of waiting passengers. Firstly, the individual and group behaviors of passengers on the platform are studied, and the actual distribution of passengers in a waiting period is selected to facilitate the division of the platform area; Based on the clustering analysis of density, Density-based clustering analysis (DBSCAN) algorithm can cluster the distribution data of passengers on the platform to realize the density division of the data set, which can effectively solve the clustering problem of the data set with uneven density distribution. Through the visualization of clustering results, it can reflect the aggregation and distribution characteristics of passenger group behavior to a certain extent.

With the “Belt and Road” initiative, the relationship between various regions and countries has become increasingly close, and container transportation has gradually developed into one of the important modes of cargo transportation. Among them, Sea-rail Combined Transport (SCT) is the most promising logistics transportation method. With the globalization of the world economy and the rapid development, Sea-rail Combined Transport is about to gradually develop into a universal international cargo transportation method. In recent years, in order to ensure that China can become an emerging maritime power, the Ministry of Transport has successively issued many policies to support it, expressly requiring the strengthening of the development of the container Sea-rail Combined Transport port station. Although Zhoushan Port has become one of Chinese important foreign trade ports, today with huge competition pressure, there is still a gap with the predetermined target. How to find the development focus and breakthrough point of Zhoushan Port is to make Ningbo Zhoushan Port’s sea rail inter-modal is an important task for building the strongest brand. In this paper, we discussed the development status of container Sea-rail Combined Transport in Zhoushan Port of Ningbo, and the modified index curve method is used to predict its future traffic demand. At the same time, the necessity and innovation of developing Sea-rail Combined Transport in Zhoushan Port are explored, and corresponding suggestions are put forward to promote the prosperity and development of Zhoushan Port.

With the continuous development of nuclear energy, the spent fuel produced by the decay of radionuclides also increases. How to ensure environmental safety through safe transportation management and effective disposal of spent fuel is a new social proposition that needs to be considered and discussed in environmental protection. Based on the Web of Science database, the bibliometric tool Histcite is used to carry out a systematic metrological analysis of the research on spent fuel transportation, compares the status and priorities of spent fuel transportation research at home and abroad, grasps the current research trends and hot issues, and analyzes the development status of spent fuel transportation safety based on trend analysis. The research results show that the research related to spent fuel transportation first started in 1972 and the number of documents is increasing; the M-K trend test analysis results also show that there are obvious mutations in the related research. The internationally influential units in the field of spent fuel transportation are mainly concentrated in European and American countries such as the United States and Sweden, and the quality of the literature is high, and they are in an international leading position. The whole process of transportation assessment and environmental risk simulation are the research hotspots in this field.

The quality of urban rail transport service has a direct influence on users’ propensity to use it. It is beneficial to evaluate the quality of urban rail transit operating service from the standpoint of user loyalty in order to improve the quality of the service. Based on the perspective of user loyalty, this paper firstly establishes the evaluation system of urban rail transit operation service quality indexes based on the principles of index selection and factors affecting the quality of rail transit operation services. Secondly, a model for evaluating the quality of urban rail transportation service is created, and the structural equation is utilized to solve the model. Finally, a case study is carried out based on the survey data from Changchun's city rail transportation system. The research results support the use of an evaluation index system and technique to improve the design of rail transit operation services in Changchun.

The suburban railway adopts the mode of combined operation of express and local trains, which can solve the problems of uneven temporal and spatial distribution of passenger flow, meet the diversified needs of passengers, improve transportation efficiency and reduce operating costs. By analyzing and summarizing the passenger flow characteristics and transportation demand of suburban railway, aiming at minimizing the total travel time of passengers and enterprise operating cost, a nonlinear optimization model of suburban railway operation scheme is established. Considering the influence factors such as minimum tracking interval constraint and cross-sectional passenger flow constraint and completes the solution of the model by Lingo. The optimization results after running express and local trains show that the total travel time of passengers is reduced by about 97 minutes, and the enterprise operating cost is reduced by 30%, which proves that the proposed model is efficient and feasible.

The braking work of the retarder directly determines its braking effect on the skidding wagon. The larger the braking work, the better the braking effect. Based on a new magnetorheological retarder, this paper analyzes the braking process of the new magnetorheological retarder and gives the calculation of the braking work of this retarder. The result shows that the magnetorheological retarder can output appropriate braking work, and the physical and mechanical properties of the magnetorheological material have a large influence on the braking work of this type of retarder.

In order to reduce the shortages caused by public health events, emergency supplies must be reasonably allocated and transportation routes must be scientifically planed to maximize the rescue effect of emergency supplies. A two-stage model of emergency material distribution-transportation was modeled, and a genetic algorithm was designed to solve combining with the relevant data of COVID-19 in Xi'an. The results show that there is a negative correlation between the shortage effect and the fair distribution of objective function in the distribution model, as well as between the transportation cost and the delay cost of objective function in the transportation model.

GeoStudio software was used to simulate the distribution of hydraulic gradient before and after the failure of the piping outlet in the double-stratum dike foundation. By comparing the changes in hydraulic gradient and flow velocity in the dike foundation before and after the failure of the piping outlet, the weak position was determined. The results show that the pressure head in the double-stratum dike foundation before the failure of the piping outlet is mainly borne by the overlying clay layer, and it is then borne by the underlying sand and gravel layer after the failure of the piping. The maximum flow velocity is transferred from the foot of the dike to the outlet of the piping.

This paper presents an analytical method for calculating the stability of rolling stock to address some overturning problems associated with the railway vehicles in crosswinds. Based on the quasi-steady theory, a calculation formula with consideration of the effects of different turbulent components and various incoming wind direction, is proposed to predict the aerodynamic forces on the moving vehicle. A steady overturning model and the dynamic multi-body simulation (MBS) are then set up to calculate the wheel unloading factor of railway vehicles. Furthermore, the characteristic wind curves (CWC) for determining the crosswind stability of vehicles are given. It is found that higher mean wind and vehicle speeds generally increase the risk of overturning. The result obtained from the static analysis can be used as an approximate overturning assessment due to the simple model and built-in margins. The dynamic effects of the track irregularity and wind turbulence make the critical wind speed in the MBS method is possible to be more precise. The calculated CWC in the study case can guide the operation and management of railway vehicles in a strong crosswind environment.

Based on the fire numerical simulation, the movement characteristics of fire smoke in the super large space above the ground interchange is studied. In view of the characteristics of the overpass tunnel with large span, large space, many diversion and confluence nodes, the smoke layer morphological characteristics and smoke temperature distribution of different longitudinal air velocity under the longitudinal smoke exhaust mode are studied, and the critical air velocity of smoke flow, smoke diffusion characteristics and smoke control technology in the overpass tunnel are analyzed. The results show that after the partition between the lanes in the same direction is removed, due to the expansion of the section, the wind velocity in the original branch ramp can not effectively suppress the smoke countercurrent, and the critical smoke exhaust air velocity will increase; After canceling the same direction partition between ramps, under all calculation conditions, except for the fire source area, the other indicators 1.8 m above the ground meet the needs of personnel evacuation and escape, and the longitudinal smoke exhaust air velocity that controls the smoke not to produce countercurrent is 3.0 m/s.

Accessibility is an important reference index in urban rail transit, urban roads, urban planning and other fields. Combining with the long-term planning map of Xi'an metro, this paper uses the Depthmap software for modeling, carries out qualitative analysis on the route map, and quantitatively distracts the accessibility of each line, transfer station and starting station. The results show that it is more intuitive and detailed to use this method to analyze the subway accessibility; Xi'an Metro Line 2 and line 8 have the highest accessibility and can fully meet the traffic demand; North Street Station, Bell Tower Station and other stations are the most accessible transfer stations; Xi'an Olympic Sports Center, World Expo Park and other important scenic spots are fully considered in the map planning.

An suitable evaluation index system was developed from the three capacities of a logistics system: risk resistance, adaptation and recovery, and innovation and upgrading, based on the connotation of logistics resilience. From 2010 to 2020, this article employed the CRITIC-entropy weight approach and the TOPSIS model to assess the logistics resilience of 29 Chinese provinces. Provincial logistics resilience has a spatial link, according to the analysis of the results' temporal and spatial characteristics. As a result, a spatial error model was developed to investigate the major influencing aspects of logistics resilience. The findings suggest that provinces in China's logistical resilience is generally stronger in the southeast, lower in the north, and mixed in the middle. There is a considerable regional spillover impact and a tendency for high and low value aggregation of logistical resilience. The development of surrounding provinces can be accelerated by provinces with strong logistics resilience. The relevance of logistics resilience is beneficial to the logistics industry's high-quality development.

According to the relevant statistics, some traffic accidents are caused by forward collision avoidance actions. During such a situation, the forward car engages in emergency avoidance operations, whereas the car behind has a short time to discover and avoid the danger, resulting in a major traffic accident. With the development of intelligent connected vehicles, driving assistance systems (DAS) will also have to contend with such extreme situations. When evaluating the performance of DAS, it is important to determine whether it can avoid forward collisions.

In view of the explosive growth of information on online travel websites and the long-term information overload of tourists, it is particularly important to plan travel routes for different tourists to meet their individual needs. The paper also establishes a travel itinerary planning model with time and cost as constraints and the highest score and shortest distance as the goal, and uses Shanghai tourist attractions as examples to provide reference and guidance for related tourism products.

Multimodal transport has attracted more and more attention in the current transportation because of the characteristics of less cargo damage, low transportation cost and convenience of transaction transportation. As one of the top ten ports in my country, Rizhao Port has a very high Excellent geographical conditions and equipment and facilities are very suitable for the development of water-rail combined transportation. In recent years, Rizhao Port has also strengthened the development of water-rail intermodal transport, and only by accurately judging and evaluating the current status of water-rail intermodal transport in Rizhao Port can enlighten and point out the direction for future development. This paper selects four secondary indicators of organization coordination, capability coordination, information coordination and government policy, uses the Topsis model to evaluate the coordination of the water-rail intermodal transportation system in Rizhao Port, and obtains the coordination of the water-rail intermodal transportation system in Rizhao Port is good, but the allocation of equipment resources in the port is still unreasonable, and all the production capacity of the corresponding equipment in the port is not fully utilized. At the same time, although the information coordination of the port is very good, it can still be further integrated with the information data of the railway system to form a more complete information platform, which will be more conducive to cooperation and communication between the two transportation systems.

With the continuous development of my country's economy, my country's road traffic is also constantly being constructed, and people's traffic travel has also shown a diversified development, which makes people put forward higher requirements for safe travel. For a long time, due to the lack of understanding of the disaster mechanism and causes of road traffic accidents in my country, the ability to prevent and control road traffic accidents in my country has been affected to a large extent. The quality of life and economic development of residents have been seriously affected. In order to reduce the probability of traffic accidents, it is very important to carry out effective risk assessment of road traffic accidents, evaluate the risk level of roads and formulate corresponding management countermeasures. Finally, taking a road as an example, the constructed road traffic risk assessment model is applied.

Bike-sharing not only provides more options for urban transportation trips but also has an important impact on the transportation system. Bike sharing plays an important role in making up for other public transport. Studies have shown that bike sharing expands the coverage of subway stations. In this paper, a time series clustering algorithm based on the K-means algorithm and DTW distance is proposed to cluster the time series of shared bicycles that transfer to subway stations. The shared bicycles transferred to subway stations are identified by building a buffer zone at the entrance and exit of a subway station. The results show that the temporal patterns of bike-sharing in different metro stations can be classified into five major categories. The temporal patterns of bicycle sharing are related to the land use characteristics near the metro stations, and for residential and commercial metro stations, the trips are more and the peak duration is longer. The travel volume is decreasing from the city center to the surrounding area. The spatio-temporal patterns of the transferred shared bicycle can provide feasible suggestions for the scheduling and allocation of shared bicycles, and provide help for optimizing urban transportation.

Ship transportation is an important channel of logistics transportation in China, which has the advantages of low freight rate and large cargo capacity. The water pollutants from transport ships during navigation seriously pollute the water environment. The traditional methods for measuring the production and discharge of the water pollutants from transport ships is costly, and the conclusions are insufficient in real-time, completeness and accuracy, which cannot meet the daily monitoring and supervision needs of the management department. The types, pollution indicators and hazards of the ship pollutants were expounded, and a calculation model of production and discharge of the water pollutants from transport ships based on AIS data was developed. The model included the calculation process and calculation method. The methods for AIS data acquisition, cleaning, thinning and regional screening were proposed. The definitions of the total number of active transport ships and the total activity degree of transport ships was put forward, and the statistical methods for them were put forward at the same time. The calculation formula for production of the domestic sewage, the calculation formula for production of the oily sewage in machinery spaces, the calculation formula for production of the ship garbage, and the calculation models of production and discharge of the pollution indicators were put forward. The definitions and calculation methods of production intensity and pollution intensity of the water pollutants from transport ships and the pollution indicators in inland areas and coastal areas were put forward, respectively. A case study on the calculation of production and discharge of the water pollutants from transport ships on the Changjiang main line was carried out. The daily AIS data of the transport ships from the source to the estuary of the Changjiang from April to November 2017 was obtained, and the parameter values were set according to the measured values and the regional emission limits. Firstly, the total number of active transport ships and the total activity degree of transport ships on the Changjiang main line in 2017 were calculated. Next, the production volumes and intensities of the black water and the gray water in the domestic sewage, the oily sewage in the machinery spaces, the ship garbage were calculated. Finally, the production volumes, production intensities, discharge volumes and pollution intensities of BOD5, CODCr, SS, TN, NH3-N, TP in the black water, BOD5 and SS in the grey water, and petroleum in the oily sewage in machinery spaces were calculated. The calculation model can effectively reduce the difficulty of calculation and work cost, improve the timeliness, completeness, accuracy and credibility of conclusions, and provide technical support for ship pollutant discharge reduction, ship supervision, and policy formulation.

This paper systematically sorted out the changing trend of the industrial structure, energy structure and transportation structure in the Yangtze River Delta region, comprehensively analyzed the impact of future economic and social development on freight demand, predicted the future evolution trend of freight demand in the Yangtze River Delta region, and put forward relevant work suggestions for the optimization of freight transport structure in the Yangtze River Delta region.

Echelon utilization is an effective way to improve the utilization efficiency of retired power batteries. However, in different development periods of the recycling market, there is different mismatch between the number of used batteries and the demand for energy storage, which affects the decision-making and optimization of new energy vehicles supply chain. To solve this problem, a closed-loop supply chain model composed of battery manufacturer, passenger car manufacturer and third-party recycler was constructed. Stackelberg game theory was used to study the recycling market in the early stage of development (the recycling quantity is greater than the energy storage demand) and the mature stage (the recycling quantity is less than the energy storage demand), and it was found that: Under decentralized decision-making, the expansion of the energy storage market scale can effectively promote battery recycling and secondary utilization, but this effect cannot be achieved under centralized decision-making. The selling price of secondary batteries is not affected by the loss of power batteries in the early stage of the development of the recycling market, and is proportional to the loss rate of power batteries in the mature period of the recycling market. In the early stage of the development of the recycling market, the cost-sharing contract can achieve closed-loop supply chain coordination, but the revenue-sharing contract cannot achieve supply chain coordination. In the mature period of the recycling market, both contracts can achieve coordination.

To study the variation law of driver's sight distance at tunnel entrance and exit, an actual vehicle test was conducted on an expressway in Chongqing (a total length of 160 km, 36 tunnels, including 4 short tunnels, 8 middle tunnels, 14 long tunnels, and 10 extra-long tunnels) in non-peak hours. Eye-tracking data, illuminance, and velocity were collected by eye-tracker, illuminance meter, and non-contact velocimetry with multi-function respectively. Based on the image illuminance extraction method, the illuminance of tunnel entrance and exit were obtained through Matlab. According to the tunnel parameters in reality, the scale model test was designed, and the driving simulation test was carried out to obtain the driver's sight distance at the tunnel entrance and exit. The support vector regression sight distance calculation model was constructed to analyze the relationship among the driver's driving sight distance, velocity, and illuminance to inspect the driver's sight distance at the entrance and exit of the tunnel and put forward some improvement measures.

In this paper, the tank model of tank vehicle is constructed by mathematical model analysis, and the roll force of tank vehicle is deduced according to the mathematical model. ADAMS software was used to build the multi-body dynamics model of tank vehicle. Simulation analysis was carried out for line shifting and turning conditions under different speed and load conditions, and the roll threshold of tank vehicle was obtained by analyzing the normal ground contact force of one side tire.

Pedestrians are the most important vulnerable road traffic participant. According to the traffic accident survey, pedestrian fatalities exceed 30% of total fatalities. Among the accident scenarios of car to pedestrian, car to pedestrian crossing and car to pedestrian longitudinal are the most frequent. Research shows that the accident rate is higher at nighttime than daytime. In this paper, based on the characteristics of road traffic accidents in China and combined with the nighttime illumination characteristics of Chinese roads, we focused on the study of automatic emergency braking (AEB) system for pedestrian nighttime test and evaluation scenarios, and carried out the validation of test methods and test techniques.

With the rapid increasing use of vehicles car ownership, the problem of road safety has become increasingly prominent. Taking the "Vision Zero" road traffic safety improvement measures in San Francisco as a research case, this paper makes a reference analyzing on the improvement of urban traffic safety in China. This paper introduces the traffic safety improvement plan of San Francisco from the perspective of “Vision Zero”, and analyzes the measures to improve traffic safety from the aspects of urban traffic safety system, urban road traffic design and urban traffic safety intelligent system. Finally, through the comprehensive analysis of the advanced experience research in San Francisco and the current situation of road safety design in China, this paper claims the "4E-AI-BD" traffic safety development strategic framework and improvement measures for the "Vision Zero".

In addition to the great prospects for development, unmanned distribution has attracted a great deal of social attention as a new type of logistics distribution mode. The use of electric unmanned vehicles for urban logistics distribution can not only reduce enterprise costs but also achieve non-contact distribution and rapid logistics response for unmanned logistics distribution in multiple distribution centers. A multi-distribution center urban unmanned logistics distribution path optimization model is developed for minimizing total cost, taking into account constraints such as battery capacity of electric unmanned vehicles, customer time windows, simultaneous pickup and delivery, and vehicle balance between distribution centers. In this study, an improved genetic algorithm was designed with a reasonable route optimization strategy, and its effectiveness was verified through a variety of calculation examples. Our model was compared with other variant models and parameters. As a result of the analysis, it can be seen that the established model and algorithm can improve the vehicle path and save the distribution costs. This research can promote the development of urban unmanned logistics distribution mode and provide theoretical reference.

As a kind of information management technology, BIM and WebGIS can provide strong support for three-dimensional model of structure, make people fully understand the specific state of structure, and solve the spatial problems maximally. This paper first discusses the characteristics of highway maintenance at present, puts forward the application of BIM+WebGIS integrated technology in the construction of highway maintenance management platform. Then, on the basis of introducing the overall framework of the platform, it focuses on the platform's three major systems: the integrated management system of highway production and maintenance, the safety management system of highway operation and the health monitoring system of bridge, are emphasized. Through the research of this technology system, the digital transformation of highway maintenance is realized, and the progress of highway maintenance management in the aspect of science and technology and intelligence is promoted, it provides reference experience for improving highway fine management by technical means.

Taking the subgrade width of high-speed railway as the research background, the indoor model test with geometric similarity ratio of 1:10 was established to simulate the working condition of high-speed railway subgrade width with or without geogrid in loess area, and the stress characteristics and settlement deformation law of subgrade width structure under two working conditions were studied. The test results show that the internal vertical stress of the widening subgrade increases with the increase of load, and decreases with the depth of subgrade. The maximum settlement occurs at the junction of existing and new subgrade, which leads to uneven settlement of existing new subgrade. After the geogrid is set inside the new subgrade, the vertical stress and subgrade settlement inside the subgrade are significantly reduced, and the uneven settlement of the subgrade is slowed down.

In view of the many factors affecting the safety of railway dangerous goods transportation, in order to objectively evaluate the effectiveness of safety management in the current national railway dangerous goods transportation process [1], based on the standard railway dangerous goods transportation safety supervision and management requirements, analytic hierarchy process (AHP) is used to analyze the present railway dangerous goods transportation status in China. From personnel, goods, technology, equipment, rules and regulations, safety management of the five aspects to develop safety evaluation system, determine the index weight, comprehensive evaluation by railway transport of dangerous goods safety situation, and according to the evaluation results to determine the safety of the different factors on the influence of railway dangerous goods transportation, provide the basis for transportation safety management.

Using the 1D/3D co-simulation method, aiming at the proposed heating scheme of the air conditioning system of the EMU, a 1D model of the heating system and control logic was built in the 1D simulation software Amesim. In the 3D simulation software STAR-CCM+, the 3D model of the ventilation system and the passenger room was built. The heating performance of the scheme and the temperature uniformity of the passenger room was verified through co-simulation. The results show that, compared with 1D simulation or 3D simulation alone, 1D/3D co-simulation integrates the previous independent models and can take into account the parameter performance and structural characteristics of the simulation object. It is more intuitive to observe the transient changes of each part of the system during the simulation process to realize the control of each part of the heating scheme, discover design omissions in advance, and improve the design efficiency, which is of positive significance.

Due to the complex topography and geological conditions of the mountainous two-lane highway, the road alignment is complex, the excavation is more, the road space is complex and changeable, and traffic safety accidents are frequent. In order to explore the influencing factors that affect the driver's visual load, this paper systematically sorts out the research on the driver's visual load in the field of road traffic safety, and summarizes the concept, influencing factors and evaluation methods of visual load. In future research, it is necessary to consider the influencing factors and changing laws from more angles, and conduct a comprehensive study.

The rapid development of road traffic generates extreme noise pollution. The current development trend from noise control by simply reducing the noise level to overall soundscape design has brought revolutionary progress in the field of road traffic sound environment. This paper reviews the current situation of road traffic soundscape research. First, it systematically analyzes the development trend and hot keywords of road traffic soundscape and its related literature with the bibliometric method. It compares the development history of the road traffic soundscape from many aspects, such as concept, research framework and model, research method. It summarizes the research hotspots of road traffic sound landscape. Secondly, from the road traffic soundscape negative design (eliminating the existing bad soundscape as the basis) and positive design (creating a harmonious sound environment), the application and research on road traffic sound landscape are reviewed. A relatively complete set of road traffic sound landscape design methods is explored to create a good audio-visual context along the road, enhance and improve people's audio-visual comfort, and meet people's audio-visual feelings and health. Finally, the current situation and challenges of existing research are systematically summarized, and the future development direction and research trends of road traffic sound landscape are analyzed from standardized research system innovation, effective combination of research and practice, and exploration of quantitative design methods.

Five different RAPs were selected to perform gyratory compaction test at different testing temperatures (60 ℃ and 110 ℃) and compaction speeds (0.5 mm/s, 1.5 mm/s, 2.5 mm/s and 3.5 mm/s). The mechanical parameters (stress and strain) were recorded through AFG2 PINEPAVETM which was incorporated into the gyratory compactor. Results show that the stress and strain increase gradually with the compaction of RAPs. Different RAPs exhibit diverse stress and strain values under different temperatures and speeds of gyratory compaction. However, the changing rate of strain is almost the same with regard to different RAPs. The properties of RAP can be indirectly reflected based on these mechanical parameters, which is helpful for the evaluation of RAP performance and design of regenerated asphalt mixture.

The past decade has seen increasing application of BIM technology in AEC projects across China with the promotion of the regional BIM support policies. However, the spatiotemporal coupling relationship between regional BIM policies and typical BIM projects in China has not been investigated. This paper constructs a comprehensive evaluation system of regional BIM policies and BIM typical projects and analyzes the coupling evolution characteristics of regional BIM policies and BIM typical projects in time and space by the coupling model. Firstly, the coupling degrees between regional BIM policies and typical BIM projects in China are at the running-in period, and the degree of coupling coordination is still in the early stages, but the overall trend is increasing as time goes on. Secondly, there is an evident regional diversity of coupling degree of China's regional BIM policies and BIM typical projects, and the coupling degree is closely related to the regional economic development, with a clear radiation-driven effect in space, showing the tendency of progressively spreading from the "core" of high coupling to the "periphery", and the degree of spreading influence has a defined direction in space. Thirdly, the type of coupling between BIM policies and typical BIM projects is advanced development policy in more than half of China's provinces.

Traditional transportation planning is based on deterministic assumptions which can result in unreasonable conclusion in the planning scheme. This paper considers the network optimization problem under the condition of cross-time decision-making. Assuming that supply and demand obey the known random distribution, we further give the network design model of stochastic bi-level programming. The objective function of the upper model is to maximize the net present value of the system, and the lower model uses traditional user equilibrium model. Genetic algorithm with Monte Carlo is used to solve the cross-time transportation network design problem under supply and demand uncertainty. The Sioux Falls network example shows that the model can be applied to medium-sized networks.

Aiming at the difficulty of accurately segmenting pavement cracks in traditional detection methods, this paper proposes a lightweight real-time detection model named MFPNet with an end-to-end encoding and decoding structure. Firstly, in the encoding stage, based on the different extraction characteristics of the involution-G and convolution operators for cracks, the designed multi-type features parallel (MFP) module is used in the deep network to enhance the abstract semantic information with reducing information loss. Then, the simplified long connection structure is adopted in the decoding stage to maintain the detection speed without reducing the detection accuracy. Additionally, ablation experiments demonstrate the effectiveness of the designed module. What’s more, compared with other deep learning-based algorithms, the model proposed in this paper has excellent performance, and its MIOU, Recall, and F1 Score reach 0.7705, 0.8023, and 0.8485, respectively. In practice, MFPNet can be implemented in images with a high resolution of 2048×1024 in real time.

In order to solve the problem of the long repair time of bridge expansion joints that may result in long road closure periods and reduced vehicle traffic efficiency, a rapid-curing cement-based mortar material was prepared in this paper on the basis of special cement material through the adjustment of formulation and mineral admixture. The optimum mortar mix proportion obtained through research is as follows: cement-sand ratio is 1:1.1, water reducer is 0.2%, and the ratio of silica fume, mineral powder, and fly ash to cement is 6%, 2%, and 2% respectively. The 2h flexural strength and 2h compressive strength of the material obtained with the optimum formula reached 7 MPa and 24 Mpa respectively. Moreover, it has good fluidity and setting time properties without an obvious decrease in long-term strength, so it is an ideal rapid repair material for bridge expansion joints.

Building intelligence has become a new requirement for the development of the construction industry in the Internet era, and the use of traditional engineering cost models for complex and huge construction projects will produce results with large data errors and inaccurate calculation results. Based on this, this paper analyzes the application status of BIM technology in engineering cost management at home and abroad, summarizes the advantages of BIM technology in the process of large-scale project cost, based on this, this paper improves the traditional construction project cost model, uses the principal component analysis method to establish a large-scale construction project valuation model, gradually reduces the external interference factors, reasonably quantifies the measurement standards, and constructs a large-scale building cost estimation model system centered on BIM. By comparing with the actual data, the experimental results show that the model is more accurate in the estimation of the project cost of large-scale projects, and the new model has certain practical significance for the study of the engineering cost of large-scale construction projects.

In recent years, with the continuous development of traffic engineering in China, many large-scale cluster projects across rivers and seas have been started and completed. As an important structural form of crossing water, immersed tunnel has been paid more and more attention. However, the joints between precast segments of immersed tunnel, especially the final joints of the closure section, are the key problems in the construction of immersed tunnel, where there are multi-directional needs such as permeability, safety, convenience and economy. The final joint technology in the construction of large immersed tunnel, such as Shenzhen-Zhongshan Link, is a controlling problem, and innovative technology is still needed. In this paper, five kinds of final joint structures and construction methods of immersed tunnel are investigated, and the characteristics of each joint are summarized and introduced. The final joint forms in the existing representative projects in China are also investigated and summarized. Finally, on the basis of the existing research, the problems that need to be paid attention to in the construction of the final joint of Shenzhen-Zhongshan Link are pointed out, which provides a reference for the construction of similar projects.

Under the national "double carbon" goal, taking the prefabricated building as the research goal, the system dynamics model of prefabricated building is constructed using Vensim software. Draw the causal circuit diagram and stock flow diagram, determine the model equation, study the relationship and action mechanism between different influencing factors of prefabricated buildings. Simulate the change trend of carbon emission of prefabricated buildings under the time series, investigate the sensitivity of eight types of industrial policy changes to the system. Taking Xi'an city as an example, the results show that the market share of prefabricated buildings in Xi'an city will reach 52%, and the total emission reduction will reach 12.56 million tons in 2030. Industrial policies play an obvious role in promoting the development of prefabricated buildings. The implementation of construction policies, fiscal policies, technical policies and ecological development policies have good effects, which plays a great role in promoting the development of prefabricated buildings and energy conservation and emission reduction in Xi'an City, and provide references for emission reduction in other cities.

Most of the newly-built pavements of airports in China are rigid pavements made of cement concrete, which have good durability, stability and high strength. However, the early cracks in the airport pavement construction may endanger flight safety. If it is not dealt with in time, the life of the pavement will be shortened and even cause flight safety accidents under the cumulative effect of aircraft impact loads for a long time and the influence of the natural environment. This paper analyzes the causes of early cracks in the cement concrete pavement of the airport and proposes a series of preventive measures to control them in combination with the expansion project of the deicing floor of Tianjin Airport.

The small clear distance tunnel formed by the combination of the newly built four-lane tunnel and the in-situ extension of the existing tunnel has become one of the important types of reconstruction and expansion of the tunnel. The reasonable clear distance of the small clear tunnel is the difficulty in design and construction. In order to fully optimize the net distance of the super-large section and small-distance tunnel, finite difference software was used to study the influence of the construction net-distance in the reconstruction and expansion of the super-large section and small-distance tunnel, and the distribution of the plastic zone in the middle rock under different net distances. At the same time, using the penetration of the plastic zone in the middle rock as the criterion, the conclusion is drawn that the reasonable clear distance of the Shenshanxi Tunnel is 1.25B. In addition, the deformation characteristics of the surrounding rock during the construction of the existing tunnel to the new tunnel are also analyzed. The results show that: (1) With the increase of the tunnel clear distance, the smaller the change of the vault settlement and invert heave value, the smaller the final cumulative settlement. From the perspective of displacement, the reasonable clear distance between the existing tunnel and the newly built tunnel should be controlled above 1.25B.

In this study, we used the SEM electron microscope to observe the morphological characteristics of each phase interface in the mixture, focusing on the effects of gradation, cement content, curing age, and mixing method on the unconfined compressive strength and splitting strength of the cold recycled mixture, to optimize the material composition design of cement composite recycled mixture. The results showed that dry shrinkage cracks and cement aggregates appeared on the surface of the three aggregates formed by conventional mixing, while the old cement that was not closely connected on the RBP surface of the mixture fell off using the vibration mixing method. The cement on the surface of all kinds of aggregates was evenly coated, with a reduced interface strength variability. The strength of the mixture increased with age was in line with the law of cement strength growth; The increase in cement content could increase the unconfined compressive strength and splitting strength of the mixture; The strength of the mixture increased and then decreased with the increase of RAP content. The unconfined compressive strength and splitting strength of the mixture were increased by 32.4% and 44.3%, and the coefficient of variation was reduced by 27.1% and 31.0%, respectively, by using vibration mixing compared with conventional mixing.

Precast pipe jacking construction technology has been widely applied in bridges engineering, however, the jacking technology in immersed tunnel is different from bridges, the former requires higher synchronization of pushing process and pushing performance of equipment. In particular, precast slide rail layout and selection of slide plate material will directly affect the effect of immersed tube tunnel. In this paper, based on the final pipe joint project of immersed tube tunnel in Shenzhen-Zhongshan Link, the research will not only carry out selection and parameter test of slide rail but also scale model test, which will further verify the engineering feasibility of the slide rail design scheme. The experimental result calculates the value range of friction coefficient of slide plate and points out the influence of machining deviation on slide rail, which provides strong support for parameters design and material selection.

In order to study the influence of multi-dimensional seismic on the seismic isolation structure considering the rotational component, a high-rise steel frame structure model was established by finite element software, and the seismic isolation layer was set up in the base layer, the sixth layer, the eleventh layer and the sixteenth layer of the structure, forming four seismic isolation structures, and the dynamic response analysis of the multidimensional seismic on the structure considering the rotation component and only the translation component was completed. The results show that considering the coupling of different seismic rotation components and translational components compared with only translational seismic components, the structural response is increased, among which the structural response is the largest when the six components of seismic vibration act at the same time, the maximum acceleration of the top layer, the maximum horizontal displacement between layers, and the maximum column end shear force increase are 17%, 22%, and 36%, respectively, and the structural response is second when the seismic rocking component and the translational component are coupled, with an increase of 12%, 18%, and 29%, respectively. The structural response of the coupling of the torsional component of the seismic vibration and the translation component was the smallest, with an increase of 8%, 15%, and 20%, respectively. The sensitivity of the seismic isolation structure to the rotational component of the seismic vibration is less than that of the non-seismic isolation structure, and the lower the position of the seismic isolation layer, the weaker the sensitivity.

Two sampling methods (bulk sampling method and stack sampling method) were selected to obtain the RAP samples. The Marshall method was used to design the mix proportion of regenerated asphalt mixture with different contents of RAPs. The performance and its variability of different regenerated asphalt mixtures were analyzed by the rutting test, low-temperature tensile test, immersion Marshall test and the freeze-thaw splitting test. Results show that the RAP obtained from the stack sampling method exhibits an improved effect on the low-temperature crack resistance and water stability of regenerated asphalt mixture in comparison with the RAP obtained from the bulk sampling method. The stack sampling method can reduce the performance variation of the regenerated asphalt mixture than the bulk sampling method.

In order to further ensure that the distance between the air duct outlet and the working face can meet the basic ventilation conditions to ensure effective ventilation when the driving face adopts the pressure-in ventilation mode, numerical simulation is carried out in this paper with the help of fluid dynamics fluent simulation software. The influences of wind speed at outlet, ratio of section width to height, diameter of air duct, location of air duct and distance between end face and air duct outlet on flow field and effective range are analyzed. The results show that the change of outlet velocity of air duct has no effect on the velocity change law of air flow center axis, but the numerical value of corresponding position changes. Under the condition that the section size of 3m×3m is set, the optimum air duct diameter is 800mm; when the air duct is located at the top Angle of the roadway and the roadway fault area increases, the effective range increases more. When the end face distance exceeds the effective range, eddy current stagnation zone will be generated.

Rejuvenators are normally applied to guarantee the overall properties when Reclaimed Asphalt Pavement (RAP) is used. However, there are few atomic-scale interpretations on the rejuvenating mechanism of rejuvenator in RAP. This study focuses on the atomic modeling of rejuvenation behavior of oxidized asphalt. Three types of asphalt models (virgin, aged, and rejuvenated asphalt) were constructed respectively for comparative analyses of thermodynamics, glass transition behavior, free volume, self-diffusion, and atomic structures. Results denote a 4.43% increment of free volume and an 11.82 °C decrease of glass transition temperature in aged asphalt is observed after blending with 10% rejuvenators. Rejuvenators increase the cohesion of RAP binder to improve its cracking resistance. A dense and parallelly stacked structure of asphaltene is formed after oxidative aging. The introduction of rejuvenators plays the role of de-agglomeration, reversing the negative effects of aging to restore the microstructure of binder thereby recovering part of its properties.

At present, the application of building information modeling (BIM) in projects is increasing in China, and the large-scale BIM volume model with redundant data seriously restricts the use of BIM technology in practical applications. In order to load BIM models more conveniently, achieve rapid online transmission, and reduce the resource consumption of computers and mobile devices, it is proposed to lightweight process BIM models by parsing and extracting IFC file information, reconstructing models, and eliminating redundant model components.

With the upgrading of urban planning and construction, resilient city construction has gradually become an important proposition to promote urban sustainable development. Resilient disaster prevention is its main content, in which the seismic resilience of lifeline bridge is particularly important. This paper conducts the seismic fragility analysis of a three-tower cable-stayed bridge to assess its seismic performance and facilitate the subsequent seismic resilience evaluation of the cable-stayed bridge. The finite element model for the bridge is established using OpenSees platform. The fragility curves of the main components of the bridge are established by adopting the fragility model based on incremental dynamic analysis (IDA), and the fragility of the whole bridge is evaluated using the narrow bound method. The results show that the tower is the most fragile component, while the failure probability of the cable is relatively low. The failure of the whole bridge is mainly determined by the tower.

To solve the problem of waste-mud accumulation both occupying land resources and polluting the ecological environment, cement is used as a curing agent to cure the waste-mud to become a perfect roadbed filler, and the engineering performance of solidified mud was studied with unconfined compressive strength (UCS), moisture content, compaction performance, and California bearing ratio (CBR) as evaluation indexes. The evaluation results show 1) that cement has a good curing effect on waste-mud and can improve its strength and stability; 2) that the water content and maximum dry density (MDD) of cured slurry decrease with the increase of cement admixture, and the optimal moisture content increases with the increase of cement admixture; 3) that CBR increases with the increase of cement admixture and maintenance days; 4) that the moisture content of cured slurry with 14% cement admixture is similar to its optimal water content (OWC) at the maintenance age of 14 d; thus, it can be considered that the curing slurry with 14% cement could be directly used as roadbed fillers.

Based on a pipeline gallery project passed through a box culvert in Xi'an city, a finite element model was built to study the effect on reducing the influence of pipe jacking construction which MJS reinforcement combining horizontal and vertical piles was adopted. The result shows that MJS combined horizontal and vertical piles can reduce the influence of pipe jacking construction. The optimal effect of internal force, vertical displacement, horizontal displacement and surface settlement of the culvert after combined reinforcement were 17.58%, 17.18%, 42.44% and 67.26%, respectively. The actual surface settlement of four sections is compared with that of combined reinforcement in numerical simulation, and the accuracy of numerical simulation is verified. This proves that the MJS construction method plays an important role in protecting existing structures in the undercrossing project.

In view of the problems and needs of structural ornaments in the artistic creation of bridge appearance, combined with the technical advantages of 3D printing technology, and from the perspective of ensuring structural safety and durability, the 3D printing materials and implementation of structural bridge ornaments are studied. The optimization of the 3D printing path and process parameters, the advantages and disadvantages of 3D printing materials are studied in detail. On this basis, the experimental research on 3D printing materials of structural bridge ornaments is focused. Through the tensile and bending strength tests, high and low-temperature cycle tests, and high-temperature deformation tests, the feasibility of applying ABS materials to the 3D printing of structural bridge ornaments is determined. The connection mode between 3D printing ornaments and the bridge's main structure and the connection mode between brackets and 3D printing ornaments are studied and proposed in detail, which provides a practical technical means and methods for the realization of 3D printing of bridge structural ornaments.

This paper aims to investigate the central composite design used to study the performance of alkali-activated slag-limestone powder cement mortar and optimize the mix proportion parameters. The results show that the alkali content significantly influences the fluidity, flexural strength and compressive strength of mortar. The interaction of alkali content and limestone powder significantly affects the 28-day compressive strength and water absorption. The established models of fluidity, strength and water absorption are accurate and effective, and the errors are less than 5%. The optimization results demonstrated that 7.55% alkali and 10% limestone powder incorporated in alkali-activated slag mortar has the highest desirability.

For the mix proportion design of bituminous mixture, gap graded SMA-13 is selected and 4‰ of basalt fiber is added to it. Moreover, its pavement performance is compared with that of the ordinary SMA-13 bituminous mixture with the same amount of lignin fiber, so as to study the effect of the basalt fiber on the pavement performance of the SMA-13 bituminous mixture. The test results show that compared with the ordinary SMA-13 asphalt mixture, the bitumen aggregate ratio of the SMA-13 bituminous mixture with basalt fiber is reduced, and the high-temperature stability and low-temperature crack resistance are improved, while the water stability is improved to a limited extent.

Aiming at the weakening of the soil-rock interface, a permeable polymer is developed in this paper, which is analyzed by combining DIC and SEM techniques. The mechanism of mechanical properties of soil-rock interface strengthened by post-osmotic grouting was studied. Through direct shear test and DIC technology, the effects of different normal pressure, water content, interface dry-wet characteristics, and curing environment on mechanical properties of the soil-rock interface were analyzed. SEM and MIP tests were used to investigate the microstructure mechanism of the soil-rock interface reinforced by infiltration grouting. The results show that the permeable polymer can improve the shear strength of the soil-stone interface mainly by enhancing the cohesive strength of the interface. The normal pressure increases the interface friction, but the interface friction coefficient decreases with the increase of the normal pressure. The water content affects the grouting effect of the polymer, and the interfacial wetting property prevents the polymer from penetrating into the interfacial direction, thus reducing the bonding strength of the interfacial. Because of the permeability of permeable polymers, the effect of the water bubble curing environment on the shear properties of the interface is less than that of the interface wetting and drying properties. SEM and MIP tests verify that the polymer effectively fills the pores in the soil and reduces the average pore size of the soil.

In view of the problem that the alkalinity of concrete planting slope protection is high and cannot meet the requirements of planting, taking into account the compressive strength of concrete, by selecting different admixtures, the trial matching test of cementitious materials and measuring their corresponding properties are optimized. The results show that it is feasible to use aluminum sulfate cement as the main part of the cementitious material; The addition of mineral admixture to the cementitious material can reduce the alkalinity, but the effect is not very obvious; Gypsum has a higher alkali control capacity than mineral admixture, and the resulting compressive strength of the concrete has reached a more ideal situation. The test shows that 60% aluminum sulfate cement mixed with 5% silica ash, 20% gypsum, and 15% mineral powder can make the alkalinity and compressive strength of the concrete reach

With the progress of times, the sensors used to monitor tunnels have been changed from resistive and isopoint-based sensors to FBG sensors with high accuracy, reliability and sensitivity. Meanwhile many researchers have proposed different monitoring methods based on fiber Bragg grating (FBG) sensors, but the effect of layout schemes on the monitoring performance of FBG sensors is rarely discussed. In this paper, the effectiveness of the hybrid algorithm for shield tunnel layout optimization is verified by proposing an improved whale algorithm to optimize the shield tunnel sensor layout with a shield tunnel as a model and simulating its loading conditions. By comparing with the traditional uniform layout, the results surface that the error of the layout provided by the improved algorithm is much smaller than that of the uniform layout direction, and the curve fitted by the curvature fitting algorithm is closer to the real curve, which proves that the method proposed in this study can better increase the monitoring performance of FBG sensors.

The polymer grouting material (PU) has been increasingly used in trenchless repair of concrete pipes and roadbeds. Investigating the mechanical behavior of the PU-concrete (P-C) contact surfaces provides a basis for further evaluating the stability of the reinforced concrete structures, which, however, has not been conducted yet. In this study, based on the shear testing results, the mechanical properties and cracking characteristics of the P-C contact surfaces were investigated, followed by establishing the damage model. Results show that the cohesion force of the P-C contact surface increases from 0.42 MPa to 1.44 MPa when the density of the PU materials increases, and there exists residual strength when normal stress is applied. The shear failure of the P-C contact surface is caused by the shearing zone, of which the thickness is about 9-10 mm. The theoretical shear stress-strain curves of the P-C contact surfaces are in good agreement with the experimental ones. The maximum relative difference between the theoretical and experimental shear strength is about 4.2%, implying that the damage model can reflect the stress-strain laws of the P-C contact surfaces under shear.

In this paper, a mathematical model of concrete face rockfill dams’ failure due to overtopping is established to simulate the interaction between water flow characteristics and rockfill materials, which is used to simulate and calculate face rockfill dams’ failure due to overtopping. The results show that the RNG k-ε turbulence model and the volume-of-fluid method (VOF method) can accurately simulate the reverse erosion of the dam caused by the vortex flow during the failure process. The whole process of concrete face rockfill dams’ failure due to overtopping mainly goes through a gradual erosion stage and a severe failure stage, for which the simulation results further reveal the failure mechanism of the face rockfill dam.

With the ever-increasing highway transport volume and the transportation development towards the heavy-duty direction, pavement rutting, which has become one of the main highway pavement diseases, is increasingly serious and generates a strong impact the traffic safety. The main method currently used to handle pavement rutting is pavement overlay by means of pavement milling and repaving. When this method is used, however, the road needs to be closed to traffic, accompanied by complex construction technologies and a high engineering cost. How to enhance the rutting resistance of asphalt concrete and reduce the later-stage curing cost is a great difficulty faced by asphalt pavement engineering technicians at present. In this study, a high-ash composite modified rock asphalt mixture was prepared and evaluated, followed by the rutting test, immersion Marshall test, freeze-thaw splitting test, and low-temperature bending test. The results showed that the composite modification of common asphalt using natural Buton Rock Asphalt (BRA) could effectively improve the high-temperature performance, low-temperature performance, and resistance to water damage of pavements, especially showing evident advantages in rutting resistance.

Accurately estimation the location and degree of structural damage is the key to verify the effectiveness of structural damage detection methods. The natural frequency and curvature mode are chosen as the damage detection indexes, and the availability of indexes is tested by setting different damage scenarios on simply supported beam. The results show that the natural frequency index can identify the location of a single damage, but the damage degrees fail to be estimated. The curvature mode obtained from the low-order mode is able to effectively identify the damage location in damage scenarios, and can reflect the damage degree.

A variable damping viscous damper is designed, which can change the size of the effective circulation area of the damping fluid under the action of external force to achieve the effect of variable damping coefficient by setting a shaped conical rod member in the damping hole. The mechanical model of the damper was derived and calculated according to the design method by combining the hole shrinkage effect and frictional energy dissipation principle. The damping performance of the dampers was tested by adding them to a six-story reinforced concrete frame structure. The results show that the pore-type variable damping viscous hysteresis damper proposed in this paper has a significant effect of variable damping at larger displacements, and the energy dissipation capacity of the damper increases gradually with the increase of the input frequency; under the action of rare intensity, the dampers have a good damping performance with the top layer displacement and acceleration reduction rate of 24.02% and 14.37% respectively for the reinforced concrete frame model structure in this paper.

The SOTIF has become the biggest obstacle to the large-scale commercial use of intelligent driving. Based on the domestic research status, this paper points out that there is a problem of heavy intelligence and weak connected in SOTIF, which deviates from the technological route of the coordinated development of intelligence and connected in China. In view of this problem, combined with my work practice, under the guidance of ISO21448 specification, this paper puts forward a SOTIF research framework for Cooperative Sensing System based on Road-side Infrastructure Support. Its feature is that it takes the vehicle perception as the core, uses the road-side perception system as a part of the vehicle sensing for data fusion and target recognition, and proposes an overall evaluation framework and quantitative index system, which provides ideas and directions for further research.

Uneven settlement of roadbed and flat scar of wheel are the main diseases of railway vehicles in operation, which have obvious influence on the dynamic response of wheel-rail system and traffic safety. In order to study the influence of two kinds of diseases on traffic safety, a vehicle-track coupling dynamic model was established, and the dynamic response of the vehicle-track system was discussed under the conditions of different settling wavelength, amplitude, speed and length of flat scar. The results show that the impact response of flat scar has great influence on the vertical force of wheel and rail and the load reduction rate of wheel weight, and the amplitude and wavelength of subgrade settlement have great influence on the vertical acceleration of vehicle body. When the train runs at 100km/h, it is recommended that the wavelength of uneven subgrade settlement is greater than 10m, the amplitude is less than 10mm, and the length of flat scar is less than 40mm.

The anti-skid performance of asphalt pavement is the key index to judge the safety of pavement, and excellent anti-skid performance is also the most effective means to ensure the safety of vehicles. In many years of road operation and management, it is found that the loss of skid resistance of asphalt pavement is the most common disease in the road. Due to the decrease of road skid resistance, traffic safety and road service quality are seriously affected. In view of the factors affecting the skid resistance of asphalt pavement, the tire factors, materials, grading types, construction technology, operation and maintenance management are summarized. This paper analyzes the reasons for the attenuation of anti-skid performance of asphalt pavement by vehicle load, running time, water and pollutants, and the relevant test methods and evaluation models of anti-skid performance of asphalt pavement.

Tunnel excavation will trigger stratum loss and overlying soil settlement. The other buildings (structures), if any, in the affected area of tunnel excavation will also be subjected to settlement. Too large settlement will lead to the shear failure of the existing structures. To explore the settlement problem incurred when the existing expressway subgrade was crossed during the large-diameter-section curved shield tunnel construction, a modeling analysis of the construction process was performed using the numerical simulation method, and the settlement laws and morphologies of the expressway subgrade were acquired. Results showed that the lateral settlement curve of ground surface presented a unipolar type. The maximum settlement was located above the tunnel axis, while the settlement decreased gradually at a long distance from the tunnel axis, and the maximum settlement was about 23 mm. Due to the settlement of soil, the expressway subgrade experienced compatibility of deformation with the soil, and finally, the lateral settlement form was consistent with that of the ground surface. The scope of influence of longitudinal settlement induced by tunnel excavation was about 30 m. When the tunnel excavation face was rightly below the settlement monitoring point, the subgrade settlement rate was high. During the construction, close attention should be paid to the subgrade settlement amount and settlement rate in the rapid settlement stage. In the face of a high settlement rate and large settlement amount, the reinforcement countermeasures should be adopted timely for the stratum and subgrade to reduce the settlement rate and settlement amount during construction, protect the expressway subgrade from large deformation-induced failure and ensure expressway operation safety during the tunnel construction.

In the process of operation, oil and gas pipelines are prone to corrosion due to the influence of transportation medium and the external environment, which leads to safety accidents. In order to study the evaluation of residual strength of corrosion defects in natural gas pipelines, the calculation methods and application scope of each evaluation standard are described in this paper. Taking a long-distance natural gas pipeline as an object, a finite element model of pipeline corrosion defects was established by ABAQUS, and the effects of defect length, depth, width, and pipe diameter thickness ratio on the residual strength of pipelines with corrosion defects were studied. Based on the failure pressure of pipelines with different corrosion defect sizes calculated by finite element numerical simulation, the applicability of each standard method was analyzed, and the residual strength evaluation method suitable for this kind of gas transmission pipeline was given.

In order to reduce the illegal crossing phenomenon of pedestrians and alleviate the conflict between people and vehicles at signalized intersections, the signalized intersections under the smart pedestrian crossing system are studied, the game analysis of pedestrians and drivers is carried out, and the internal mechanism of pedestrians is studied. By using game theory to study the internal crossing mechanism between pedestrians and drivers at signal intersections, it is found that the facility can effectively reduce the conflict between pedestrians and vehicles at signal intersections, improve the crossing efficiency of pedestrian drivers and protect the safety of pedestrians crossing the streets. It is more conducive for pedestrians to abide by traffic rules, establish the concept of civilized traffic, and promote social civilization.

Flex-route feeder transit is a promising way to improve the flexibility of first/last mile service. In this paper, we propose an optimal scheduling strategy which can provide immediate feedback to enhance the attraction of flex-route feeder transit. An improved cycle length model and a modified scheduling algorithm are proposed to guarantee the performance and the reliability of feeder system. Six indicators are employed to evaluate the performance of flex-route feeder transit from macroscopic and microcosmic aspects. Finally, simulation experiments with different system parameter values are conducted using the proposed model and algorithm. The results verify the validity of the optimal method and indicate that our optimal design for flex-route feeder transit can help the decision-makers best select from the transit modes in different situations.

With the expansion of industrial manufacturing, a single motor is difficult to meet the needs of production, synchronous operation mode of multiple motors has been widely used in industry and production. This article takes four permanent magnet synchronous motors as the research object and adopts SVPWM control technology as the inner loop to achieve steady-state operation of every motor. The outer loop adopts conventional PI controller and sliding mode controller (SMC) to realize synchronous operation of four motors respectively. Based on the Matlab/Simulink platform the simulation model of the synchronous motor control system is designed. The deviation coupling synchronization control strategy of four motors under different speed outer loop control modes is studied. Through the load torque mutation experiments, the anti-disturbance ability and rapidity of the two controllers are compared. Simulation experiment results show that the multi-motor synchronous control system based on sliding mode controller still has good speed tracking performance under large load torque sudden changes.

The township territorial spatial planning is the most basic part of the "five levels and three types" territorial spatial planning system, with the aim of realizing the precise landing of all kinds of territorial spatial elements and establishing a "one blueprint" for the whole area of the township as the main work content. In addition to strictly following the technical specifications or standards set by the state, its preparation should also combine the characteristics of regional resource background to determine feasible measures that can effectively guide the protection and utilization of local natural resources. This paper mainly focuses on the township territorial spatial planning as the research object, combined with the preparation practice of "Wuhan Xinzhou District Sandian Street Street Territorial Spatial Planning (2020-2035)", from the background and significance of the preparation of the township territorial spatial planning, research and analysis, evaluation and judgment, and other perspectives and links, and then sort out how to scientifically formulate the planning positioning and development goals of the township territorial spatial planning.

As an important basic unit of China's administrative division, townships play an important role in coordinating urban-rural relations and promoting urbanization, and the scientific and effective preparation of township-level territorial spatial planning is related to the healthy economic and social development of China's urban and rural areas. The reconstruction of the territorial spatial planning system in the new era has put forward new requirements for the connotation of township-level planning. Based on the analysis of the basic characteristics of China's townships and existing planning problems, this paper mainly focuses on the townships' territorial spatial planning, combining the practice of preparing the "Territorial Spatial Planning of Sandian Street, Xinzhou District, Wuhan City (2020-2035)", starting from the background and significance of the preparation of the townships' territorial spatial planning, evaluating and judging the current situation in conjunction with the relevant planning and index requirements, and exploring how to scientifically formulate The planning orientation and development goals of the township territorial spatial planning.

In the design of transmission lines, the selection of suitable wires is of great significance to the project. In this paper, finite element software ANSYS was used to establish finite element model of transmission tower, three towers and four-wire finite elements of ordinary steel core aluminum strand and carbon fiber composite core conductor, which calculates the displacement, axial force and bending moment of the transmission single tower, the ordinary steel core aluminum strand before the transformation and the carbon fiber composite core wire tower system after the transformation. The analysis results show that the top displacement of the tower, in the tower line coupling system of ACCC conductor, is about 48.9% higher than that of the transmission tower, and the axial force and bending moment of the bottom of the tower, are about 39.6% and 37.9% higher than that of the transmission single tower, which indicates that the coupling of the tower line needs to be considered when the ACCC wire is used for the transmission line. The maximum displacement of the tower top under the ACCC wire is reduced by about 62.7%, compared with the maximum displacement of the tower top under the action of the ACSR wire, and the maximum axial force and bending moment of the bottom of the tower are also reduced by about 64.2% and 64.7% , which explains that the carbon fiber composite core wire after the transformation has more superior performance than the ordinary steel core aluminum stranded wire used for transmission lines before the transformation.

With the rapid development of information technology, the manufacturing industry is transforming to digitization and intelligence. The realization of real-time interaction and data fusion between physical factory and virtual factory is one of the bottlenecks to realize intelligence. To avoid this issue, it is necessary to design a dynamic monitoring system of prefabricated component production line based on digital twin technology. The system architecture includes physical layer, data layer, virtual layer and application layer, and the interconnection of all levels of the monitoring system is realized by using information technologies such as the Internet of Things, PLC and MES. Through data integration display and virtual factory display, the on-site comprehensive monitoring and intelligent simulation analysis of the production line can accurately locate the abnormal conditions in the production process, which can provide early warning and optimization decisions quickly. The results show that the system can monitor and predict the production line in real time, and has good practicability, which can provide a reference for the realization of dynamic monitoring of the production line.

The UAV flight plan should comprehensively consider the influence of slope environment, slope safety level, geological conditions, UAV flight conditions and other factors, so as to determine the applicable environment and conditions for rapid and fine patrol inspection and define the patrol inspection plan for different types of slopes under different safety status and other levels. Combined with the current and future project inspection requirements and inspection contents, the main contents and inspection requirements for UAV inspection to obtain high-definition images under different inspection schemes are formulated. The development of highway slope inspection equipment was carried out. According to the slope inspection requirements and inspection contents, the selection principle of UAV was determined, including camera accuracy, hovering stability, camera zoom and focusing, etc. Finally, the "Royal" mavic two zoom version produced by Dajiang company was selected as the slope inspection equipment. The UAV slope inspection equipment has been developed, and the functions of slope inspection task establishment, task execution, image shooting, uploading and downloading have been successfully realized. The standardized operation process and method of UAV patrol inspection are established.

With the improvement of the level of autonomous driving vehicles, the software and hardware structure of the autonomous driving system becomes more and more complex, so ensuring the safety of autonomous driving vehicles is the most important safety issue. At present, the commonly used test methods include closed sites, open roads, and simulation tests. The test focuses on conventional road sections, traffic objects, and sunny weather, but the actual driving process of vehicles encounters complex environments and scenes. In this paper, the exploration and practice of the hardware in the loop simulation test method of the automatic driving awareness system on foggy days were carried out, the working performance of the automatic driving awareness system under different visibility on foggy days was analyzed, and improvement suggestions were put forward for the measured sensors.

The operation of the regional logistics network is often interrupted by emergencies such as rainstorms and earthquakes, especially the COVID-19 pandemic in recent years. Therefore, it is particularly important to improve the toughness of the regional logistics network to resist the risk of emergencies. This paper firstly constructed a multi-layered weighted regional logistics network of highways and railways in the central region of China based on the gravity model, analyzed its network structure characteristics by using dominant flow and social network analysis methods, then simulated the evolution trend of network toughness under different strategies. Finally, the optimization model of logistics network structural toughness under fixed cost was proposed to explore the optimization path of network structural toughness. The results show that: (1) The economically developed cities are located in the core area of the regional logistics network, on the contrary, they are located in the edge area of the regional logistics network. (2) The network as a whole has formed a “two main and four auxiliary” distribution pattern with Zhengzhou and Wuhan as the two main cores in the north and south, and Taiyuan, Hefei, Changsha, and Nanchang as the four auxiliary cores. (3) The network has higher toughness under the node random order failure strategy than under the node specified order failure strategy, and the optimization plans improve the structural toughness of the regional logistics network by 11.68%.

Under the background of increasing car ownership and frequent traffic accidents, this paper focuses on fatigue driving, an important cause of traffic accidents, and mainly discusses the detection method of driver fatigue driving. This paper first sorts out the traditional subjective and objective detection indicators and judgment standards for fatigue driving, analyzes the advantages and disadvantages of the traditional detection methods, and lists the commonly used public data sets; At the same time, this paper further summarizes the commonly used driver facial feature recognition and extraction methods, list new fatigue driving detection methods based on machine learning and deep learning to improve the shortcomings of traditional detection and improve detection accuracy, and finally summarize and prospect the fatigue driving detection technology. The research believes that fatigue driving detection methods based on deep learning are the general trend, which can achieve high-precision, real-time and fast fatigue detection.

The defect of underground drainage pipes is the main inducing factor of urban disasters. However, existing detection robot has problems such as poor environmental adaptability and a low degree of automation for pipes. The deep learning-based amphibious robot designed in this study is a highly adaptable and efficient detection system. The designed ducted screw propelled wheels first provide power. Next, based on the multimodal sensors and the improved YOLOV4-Tiny, defect detection and 3D reconstruction are carried out. Finally, the defect location and image information are transmitted to the terminal for display by wire, and a detection report is generated. What’s more, the experimental results show that the MAP of the improved YOLOV4-Tiny in this research is improved by 2.18% compared with the baseline network, and the FPS is improved by 11.3 frames. The system proposed provides a new approach to drainage pipe inspection.

At present, most of the research on the proportion of urban complex formats in China focuses on single-function formats, and is less carried out from the perspective of the interactive relationship between different formats. Through the analysis of various types of mixed format products such as transportation and tourism, fully considering the multi-factor comprehensive effect, and combining the actual situation of Suzhou City, this paper conducts an empirical study, trying to explore the site selection points, format ratio and spatial development strategy of traffic and tourism integration products in non-core areas of the city, so as to provide new development ideas for the high-quality development of traffic and tourism integration products in non-core areas of the city.

Nowadays, the rise of various unexpected incidents on a global scale makes the management and control of emergency transportation popular research in the field of the transportation infrastructure network. The development of digital technologies has injected new impetus into emergency traffic management in recent years. Such advancement poses a significant impact on the efficiency of evacuation, resource dispatching, and supplies technical support for the construction of emergency transportation system. In this study, we review recent literature on digital emergency disposal technologies of the transportation infrastructure network, including geographic information system (GIS), Internet of things (IoT), cooperative vehicle infrastructure system (CVIS), big data technology, and intelligent transportation system (ITS), etc. It is found that digital technologies have unique advantages and application potential in the prevention, early warning, and rescue of unexpected accidents than traditional emergency transportation management. Finally, we summarize the characteristics of the current effort and propose future research directions.

In order to improve the design quality and efficiency of special-shaped steel formwork for Flow Channel, BIM parametric design method is studied. Firstly, according to the shape design results of the flow channel, we sort out the inner wall parameters of the steel formwork, write the parametric modeling code, and drive the automatic modeling of the steel formwork shell. Then, according to the results of the reinforcing design of the steel formwork structure, we divide the outer surface of the shell into physical and chemical UV grids, and the isotropic reinforcing ribs are created adaptively. BIM parametric design has the advantages of visualization, automation, and simulation, and its universality and accuracy are significantly improved compared with 2D design. The BIM model can also be applied to finite element calculation to improve the quality and efficiency of complex structural design.

Traffic volume surveys are a key factor in determining the state of road traffic and are a necessary basis for activities such as traffic planning, road construction, traffic control and management and engineering economic analysis. Most traffic volume surveys count vehicles separately by type, so accurate identification of vehicle types is particularly important. This paper is based on traffic volume survey data from eight detection methods for different vehicle types with separate detection counts. Statistical and correlation analyses were carried out separately, culminating in a multiple linear regression model, which yielded specific relationships between the effects of the different models when performing the tests.

Under the new situation, strengthening architectural design and urban planning and design can effectively improve the effect of urban construction, promote the continuous development of the city and improve the potential value of the design scheme. It is precisely because of this factor that the current research needs to reasonably control the design scheme in combination with the current situation, so as to improve the overall effect of architectural design and effectively enhance the vitality of urban development. From the perspective of risk assessment, this study uses the grey clustering algorithm to verify the scientificity of the method. The experiment shows that the grey clustering method has a good effect on the scientific evaluation of architectural design.

With the development of modern logistics industry, as an important part of warehouse logistics system, location planning plays an important role in ensuring the production and operation of enterprises, reducing storage costs and the error rate of orders. Aiming at the logistics of auto parts, this paper puts forward a storage location planning model of spare parts, considering the factors such as order data, transportation cost, transportation frequency and so on. Then, an allocation model is established based on EIQ analysis and classified storage principle, and the integer programming model is solved by lingo software. Finally, the validity and practicability of EIQ analysis and location planning model are verified by an example, which provides a theoretical basis and decision support for the location planning of spare parts warehousing enterprises.

Freight traffic of civil aviation has developed rapidly because of its advantages of fast transportation speed and high safety. The fluctuation of freight traffic of civil aviation has brought many challenges to air traffic scheduling. If the freight traffic of civil aviation volume can be accurately predicted, the difficulty of air traffic scheduling will be reduced and the transportation efficiency of air cargo will be improved. The current prediction model can’t properly respond to the impact of emergencies. And it is not sensitive to the trend variations caused by policies, epidemics and other factors. In this paper, based on the autoregressive integrated moving average model (ARIMA) and linear regression model (LR), a hybrid ARIMA-LR model is proposed by using an improved Bayesian combined model. Through the prediction of the actual freight traffic of civil aviation volume, it is found that the hybrid ARIMA-LR model can not only better adapt to the changes caused by emergencies, but also have higher overall prediction accuracy than the ARIMA model and LR model. The three indicators of mean absolute error (MAE), mean square error (MSE) and mean absolute percentage error (MAPE) of the hybrid ARIMA-LR model are 1.06,29.02,0.03 lower than that of the ARIMA model; compared with the LR model, it is reduced by 3.00,92.00,0.06.

Pavement cracks are one of the manifestations of early road defects, which affect the safety and performance of roads. However, shadow, illumination, and other environmental factors will affect the detection performance of the algorithm, resulting in the reduction of the detection effect. This paper presents a multimodal image transformation technology to reduce the interference of shadows on crack detection. In this method, multidimensional features of infrared and visual images are obtained and registered by the multiscale registration method. Next, the Cycle-Gan model is used to learn the feature mapping relationship between infrared and visual images, and image transformation is carried out. Finally, the pre-trained U-net model is used to detect the processed image. The proposed method can effectively reduce the image's shadow area without destroying the pavement's crack structure and improve the detection performance compared with threshold-based image processing and deep learning-based DSC algorithm. In addition, its MIOU, MPA, Recall, and F1 score reach the highest of 0.7869, 0.93295, 0.7092, and 0.7870, respectively, which can provide new ideas for health detection of pavement cracks under shadow interference.

As a part of Smart City, modeling the road network for indoor route planning has become a research hotspot in recent years. This paper presents an automatic extraction method of modeling for indoor route planning. At the very beginning, an optimized Constrained Delaunay Triangulation (CDT) was used to form indoor spatial routes, on the ArcGIS, ArcEngine and Microsoft Visual Studio 2012 (VS 2012) platforms. The optimization of CDT was achieved by increasing the constraint points at the edge of the region, resulting in a more refined division of the region. After the spatial routes connect with connection points, the indoor route planning model of the road network then was formed, implemented the Dijkstra algorithm to get the planned route. Finally, to further evaluate the optimized CDT. The CDT before and after optimization is used to automatically generate the road network model of a plane floor of the building, to provide an intuitive comparison. The results proved the effectiveness of the optimization method.

Signal timing at urban intersections is a key factor affecting the overall traffic efficiency of intersections and road networks. Time segment and periodic control is a commonly used and effective control method. Based on the K-means clustering method, combined with the spatial-temporal characteristics of intersection traffic flow and the key influencing factors of signal timing. This paper studies the impact of different sample data on the intersection time-segmented timing plan, and selects four samples: the flow of all lanes at the intersection, the average flow of a single lane with the same lane function, data for a single day of the week and full data for seven days a week for clustering time division, timing plan design and simulation evaluation of intersection operation efficiency. The results show that the K-means clustering results based on the four sample data are significantly different. The average queuing and average delay of the intersection of using the average flow of a single lane with the same lane function for clustering and signal timing plan design, are generally less than the design plan after clustering using the flow of all lanes at the intersection; under the same single lane average flow with the same lane function, the cluster timing plan on a typical day of the week (such as Wednesday) is 30% lower than the cluster timing scheme with all data seven days a week, and the average queue length at the intersection is not much different.

In order to effectively deal with emergencies and mitigate the possible consequences of various emergencies, this study uses the K-means clustering method to tackle the problems of the indeterminate number, location, and coverage of the existing emergency supplies preset points. Combined with the distribution of demand points, the size of demand, the distribution distance, the location of the reserve and other factors, the 165 demand points in Xuzhou are regionally divided, and the contour coefficient is used as the evaluation index to determine the optimal number of clusters of demand points. Then through python programming, a relocation model is constructed, and the demand weight and distance are used as influencing factors to traverse all demand points in different clustering areas, thereby determining the reserve of each clustering area. The research results can optimize the location of the reserve, reduce the rescue cost, and provide a reference for the location of the reserve for emergency supplies in China.

With the problems such as urban traffic congestion, traffic safety and environmental pollution getting severe increasingly, the development of traffic perception system has attracted more and more attention around the world. This paper analyzed the situation and drawbacks of current traffic perception system, and put forward a brand-new idea based on vehicle-road cooperative perception. This paper focused on each subsystem of the traffic perception system, analyzed the key technologies of multi-source traffic data fusion perception, multi-target association and trajectory tracking in data processing dimension. By perceiving or collecting information about vehicles, road environment and traffic running conditions in the road network, it is possible to realize data sharing between vehicles and roads.

Periodic crack inspections are greatly required for the operation and maintenance of the pavement. With the rapid development of the deep learning (DL) method and the computer hardware, manual visual inspections have been gradually replaced by DL-based inspections due to their high efficiency and low cost. In this study, a novel segmentation model was proposed to conduct precise identification of cracks. Firstly, the YOLOv5 was adopted as basic detector for the coarse prediction of the crack type and crack location. Secondly, a mask branch was customized and incorporated into the aforementioned detector for parallel mask production. In addition, the neck, a feature fusion component, was upgraded to produce higher-quality masks, and a sampling-free approach was investigated to reduce class imbalance's influence. Compared to a normal segmentation model, the proposed method demonstrated a better balance between accuracy and speed, with a speed of 33.2 frames per second and an accuracy of 87.13 mAP.

In recent years, several collapse accidents of the falsework frame system appear from time to time during construction. However, few studies are focused on the influence of eccentric loading from uneven concrete pouring on the falsework system. Finite element software ABAQUS is adopted to calculate the static force of a typical type of falsework which is commonly applied in practice engineering. The stress distribution pattern and deformation of steel falsework are considered under two working conditions - eccentric load and uniform load. The vulnerable points and vertical deformation of the top beam on falsework are indicated in this paper. The stress distribution of falsework is briefly analyzed from three aspects: modelling, loading and calculation results. To help improve the negative influence from eccentric loading during construction, a falsework monitoring system utilizing IoT to detect and report abnormalities prior to the occurrence of an accident is proposed. The research and design of special new sensor devices, communication means and the adopted IoT means to improve safety of falsework is briefly introduced.

Through the application of building information modeling (BIM) technology in the Xiaowan Interchange project, this paper reviewed the idea and the correct process of the establishment of the whole complex municipal interchange BIM model in detail, studied the technology application of earthwork adjustment, collision detection, visual distance detection and headroom detection based on BIM technology, and finally tried BIM mapping and VR display. The research shows that the application of BIM technology in the design of municipal interchange can effectively optimize the linear shape, longitudinal section, structure, and position of the intersection; and the use of the BIM model to carry out a statistical review of engineering quantities and 3D mapping can improve the quality of design documents and express the design intention with a better visualization.

Traffic congestion prediction is the premise to solve the problem of traffic congestion. Aiming at the problem that traffic volume was rarely considered in traffic congestion prediction based on spatio-temporal characteristics, this paper added two features of bus flow and time occupancy on the basis of temporal correlation and spatial correlation analysis of speed based on floating bus data. A BP neural network speed prediction model optimized by whale optimization algorithm (WOA) considering the temporal and spatial characteristics of bus flow was proposed, and the traffic state was divided into three levels by fuzzy theory. The results show that the speed prediction method based on temporal and spatial characteristics and bus flow characteristics proposed in this paper has good performance. Compared with the traditional BP neural network prediction results, the root mean square error and mean absolute error of WOA-BP neural network prediction model are reduced by 11.7% and 11.2% respectively, and the determination coefficient reaches 93.7%. The prediction accuracy of traffic congestion based on fuzzy theory is 90.06%, and the prediction accuracy of the model is higher.

Aiming at the problem of color fading of existing railway signals in our country and the problem of chromaticity coordinate shift in special weather conditions, an idea of a lamp panel with adjustable lamp color is proposed. According to the Spyro extremum principle, the lamp panel array is analyzed and designed, and the red, green and blue (RGB) three-color light mixing is analyzed according to the Glassman color mixing law and the light mixing principle of the International Commission on Illumination (CIE) standard chromaticity system. The feasibility of modulation is established; the functional relationship between duty cycle, chromaticity coordinates and correlated color temperature is established respectively, and the modulation simulation and experiment of three RGB channels are carried out by means of pulse width modulation. It can be seen from the verification results that controlling the RGB three-color LED lamp beads according to the duty cycle can accurately set the relevant chromaticity coordinates of each color light, and realize the chromaticity in different situations. The light panel is expected to solve the problem of signal color decay and chromaticity coordinate shift in special weather conditions.

As a typical complex system, the requirements of stakeholders such as market, customers and operating conditions have an important impact on the design EMUs. At present, the EMU manufacturers still adopt the idea of traditional system engineering to decompose the requirements, resulting in the lack of traceable links between requirements and design, which seriously prolongs the product development cycle and increases the development cost. Under this background, this paper introduces the idea of model-based systems engineering (MBSE) into the EMU requirements management. The method is vertically divided into four aspects: the L1 layer is customer requirements, the L2 layer is product requirements, the L3 layer is system requirements, and the L4 layer is component requirements; the horizontal activities are divided into five steps: requirements capture, requirements analysis, requirements confirmation, requirements allocation, and requirements verification. It is applied to the requirements management of EMUs air conditioning system, and the results show that the application of MBSE to EMUs requirements management can establish the traceability relationship between requirements and design, ensure the accuracy of requirements, improve the efficiency of requirements management, and realize the transformation of EMU requirements from “document based” to “model-based”.

Digital twin (DT) is one of the key technologies to promote the digital and intelligent development of metro vehicle bases. Related research is at the initial stage. How to realize the digital twin generation of vehicle bases is an urgent problem to be solved. The article briefly introduces the application of digital twins in the automatic field inspection operation management system of the vehicle base, and studies the system architecture. The digital twin technology realizes operation standard monitoring, operation quality backtracking, production safety monitoring, and business statistical analysis. And so on, so as to realize the "intelligent, efficient and safe" intelligent maintenance workshop.

The platform door system is arranged along the edge of the platform, completely isolating the platform area from the tunnel track area, with a continuous barrier corresponding to the train door, which can be opened and closed by multi-level control of the sliding door, reducing the exchange of hot and cold airflow between the platform area and the track area, reducing the load of the station cooling system, and reducing the air conditioning energy consumption of the environmental control system; the normal pull in and departure of trains and the subway platform door system are closely linked. In this paper, typical faults of the platform door system are analyzed; the platform door body must be insulated in order to effectively reduce the risk of electric shock to passengers since subway riders may come into contact with it or the platform door when getting on and off the train. This paper first analyzes the basic principles of the platform door system door body insulation setting, then elaborates on the platform door system insulation problem for analysis, then introduces the corresponding solutions for the related problems, and finally specifies the platform door body insulation program.

The monitoring of passenger flow congestion in subway stations is the key to passenger flow analysis and safety control of rail transit. For the problem of passenger flow monitoring in subway station, a real-time monitoring method of passenger flow congestion based on surveillance video is proposed in this paper. Considering the characteristics of high density and serious occlusion of passenger flow in subway stations, this paper constructs a real-time monitoring model of passenger congestion in subway stations based on improved YOLOv3 is built. Firstly, YOLOv3 algorithm is modified as follows: CIoU is introduced instead of IoU to calculate the regression loss function of the target bounding box, which improves the positioning accuracy of the target bounding box; the Focal Loss function is added to guide the model to focus on the training of hard-to-class samples with high occlusion; the K-means clustering algorithm is introduced to re-cluster on the self-made dataset to obtain the anchor boxes suitable for subway station passenger flow. Then the congestion level of different areas in subway stations is divided, and the method of passenger flow congestion identification is given. Finally, an experiment is carried out based on the self-made subway pedestrian dataset SOP. The experimental results show that the average accuracy of this method increases from 92.11 % to 94.45 %, the average detection speed increases from 28.634 fps to 29.681 fps compared to former algorithm, which can meet the requirements of real-time and accuracy of pedestrian detection in subway stations.

The vehicle body overvoltage caused by the frequent passing of high-speed trains through the neutral section device seriously threatens the safety of train operation. The power supply phases at both ends of the neutral section device at the traction substation are different, and the vehicle body overvoltage caused by them is also different, so its characteristics need to be studied. At this stage, the treatment of vehicle body overvoltage focuses on the improvement of grounding device, but the effect is limited, so it is necessary to propose new methods to reduce vehicle body overvoltage. In this paper, the simulation model of the train passing the neutral section device of the traction substation is built, and the characteristics of the vehicle body overvoltage under different phase differences are simulated and analyzed. Aiming at the most serious situation of overvoltage, a new vehicle body overvoltage reduction method is proposed, and its effectiveness is verified by simulation, which provides a new idea for the reduction of passing the neutral section device vehicle body overvoltage.

In order to reveal the electric field characteristics of the catenary section insulators under normal operating conditions. Based on the FEM of the electrostatic field, a simulation model for the numerical calculation of the electric field of a single insulator and an integral catenary section insulator under normal operating conditions is established. The model uses artificial truncation method to limit the air domain, setting and defining the various parameters reasonably. The results show that the overall trend of the surface potential of a single insulator and an overall section insulator is determined by the setting of the potential, and the potential rises from the low-voltage end to the high-voltage end, and vice versa. The electric field distribution is generally U-shaped. Compared with a single insulator, the electric field of an integral section insulator decreases at the high-voltage end of the insulator, rises at the low-voltage end, and changes in other parts are not obvious. When the potentials of the fittings at both ends of the integral catenary section insulator are different, the number of fittings and the model structure have a greater influence on the distribution of potential. Derived from the electric field diagram that the maximum electric field intensity of a single insulator and an integral catenary section insulator are less than the electric intensity peak of air in a uniform electric field. There will be no corona on the surface of the insulator, which meets the requirements of insulation performance. The analysis results provide theoretical basis and reference for the design, modification and comparison of insulation characteristics of section insulation.

Roof monitoring of running trains can effectively monitor the key components of the roof. In order to check the status of key components on the roof, it is necessary to check the roof surveillance video, which is often time-consuming and labor-intensive. In order to improve the efficiency of status inspection of key components, this paper proposes a key frame extraction algorithm for roof video surveillance based on saliency detection. The algorithm first designs a saliency detection network, which is used to extract candidate video frames containing key components. Then, through feature clustering analysis, the candidate video frames are classified into frame sequences containing components attached different classes, and finally the correlation is calculated for all frames in each frame sequence and the frame with the largest correlation corresponds to the key frame of the current frame sequence.

The accurate prediction of passenger turnover is an important foundation and one of main basis of passenger transportation organization. It is also an important guarantee for the transportation industry to face the market and grasp the future. This paper used the grey correlation prediction theory to construct the GM (1,1) model. Based on the historical data of China's passenger transport before 2020, this paper respectively predicts the turnover of China's railway passenger transport, highway passenger transport and aviation passenger transport in 2030. This study shows that the prediction accuracy of the model is relatively higher. Prediction values are also basically in line with the actual development of China’s passenger transport in the future. Under the background of carbon peak, the results predicted in this paper can provide reference for the adjustment of the current passenger transport structure, and have certain significance for the development of passenger transport.

As well as known, fixed-roof tanks are vulnerable to fire and explosion accidents. To ensure the safe operation of atmospheric vertical fixed-roof storage tanks, it is essential to conduct fire and explosion risk assessments. In order to overcome the subjectivity of traditional analytic hierarchy process, improved analytic hierarchy process, and fuzzy fault tree analysis in the risk assessment of storage tank fire and explosion, a modified analytic hierarchy process was proposed in this paper. Meanwhile, the judgment matrix of modified analytic hierarchy process was constructed based on the optimized structure importance of the bottom event of the fault tree. Then, the weight factors of all indexes were calculated to evaluate the fire and explosion risk of the storage tank with fixed roof.

As an all-round emerging branch of the construction industry, large-span steel structure engineering has a long on-site construction period, complex on-site construction process, and a series of uncertain unfavorable factors. The resulting risks will directly affect the smooth progress of large-span steel structure projects. In order to improve the effective control of risks in the construction stage of long-span steel structures, a risk assessment model for the construction stage of long-span steel structures based on variable weight theory is proposed. The WSR system method is used to analyze the construction risks, and a comprehensive evaluation index system for risks in the construction stage of large-span steel structures is constructed. With the help of the variable weight comprehensive model, the two-dimensional cloud model is used to comprehensively evaluate the risks of the large-span steel structure in the construction stage from the two dimensions of risk hazard and risk probability. Finally, the two-dimensional cloud image is drawn through MATLAB and the fit degree is calculated to further determine the evaluation result. Taking a large-span steel structure stadium in Lanzhou City, Gansu Province as the research object, a comprehensive assessment of the risks of the large-span steel structure construction stage was carried out, confirm the applicability and effectiveness of the model.

Based on the Mohr-Coulomb strain softening model, the nonlinear CWFS criterion of friction strengthening and cohesion weakening is adopted, and the deterioration behavior of tensile strength and stiffness modulus caused by tensile-shear coupling yield of intact rock mass is considered. Through two different modeling methods, the influence of geometric characteristics of straight wall arch tunnel section on the failure of surrounding rock and rock-burst is simulated. The results show that the geometric characteristics of tunnel section have obvious influence on the stability of surrounding rock. The rise-span ratios are 0.5, 0.297 and 0.16, and the height of straight wall is 0.875 m. The plastic zone, rock-burst zone, tensile yield zone and shear strain localization zone of surrounding rock decrease with the decrease of rise-span ratio. When the rise-span ratios are 0.5, 0.297 and 0.16, and the vertical wall heights are 0.875 m, 1.23 m and 1.47 m, respectively, the plastic zone, rock-burst zone, tensile yield zone and shear strain localization zone of surrounding rock increase significantly with the decrease of rise-span ratio. When the rise-span ratio is 0.16 and the straight wall height H4 = 1.47 m, the maximum shear strain increment is about 10-2 , which is an order of magnitude higher than other schemes. According to Russense rock-burst criterion and shear strain localization results, the rock-burst units are mainly concentrated in the top and bottom of the tunnel section, which is consistent with the rock-burst position recorded in the field tunnel.

In this paper, we propose a new automatic test and evaluation method that can be used for autonomous driving systems in virtual simulation test. Aiming at the problems that the existing automated test method cannot guarantee coverage and validity of the test scenarios, and evaluation lacks the consideration of the complete development life cycle of the systems, we firstly introduce a new scenarios generation method that can generate scenarios with higher overall effectivity on the premise of ensuring coverage. Then, an integrated test platform is constructed, in which the components can be automatically invoked by test scripts. Finally, the automated iterative regression testing is used to ensure the effectiveness of the whole development and test process. The application and verification of a level three (L3) Traffic Jam Pilot (TJP) system is carried out on the above-stated method. The result shows that the proposed method can effectively detect system defects and significantly improve test efficiency.

Today, as the construction of smart cities is increasingly advanced, it is necessary to strengthen the cognition in the process of smart city construction, determine the influencing factors and reduce construction risks in a targeted manner. The influencing factors are divided into three levels: technology, enterprise, especially government. The DEMATEL model is used combined with Excel and Matlab software to quantify the degree of influence, and the key factors are obtained from the ranking of centrality and causality. Based on this, a smart city evaluation index system is constructed and the weight of each index is calculated. Finally, the fuzzy comprehensive evaluation method is used to evaluate the level of smart cities in 31 provinces (autonomous regions) in my country from 2014 to 2017. The research results show that there is a certain relationship between the government's scientific research and technical support policies, innovation 2.0 technology, enterprise informatization and smart city construction. Based on this, three rationalization suggestions are put forward in order to provide theoretical reference for the development of smart cities in the future.

For the local urban regional traffic with multiple road intersections, the modeling and simulation are carried out in combination with the background of private car commuting, and a private car travel model based on agent cellular automata model is proposed. The effectiveness of the model is verified by analyzing the real traffic scenarios such as recurrence following, acceleration and deceleration, and starting and stopping at traffic lights. The impact of the number of private cars and whether traffic lights are set on the roads on the traffic efficiency of urban areas at multiple intersections is discussed with the average waiting time as the index. The results show that the model can effectively simulate the driving behavior of private cars. The average speed is inversely proportional to the number of private cars and directly proportional to the average waiting time. Setting traffic lights can increase the number of stops. When local traffic flow is not saturated, setting traffic lights will affect traffic efficiency. When local traffic flow is saturated, setting traffic lights can reduce traffic delay and waiting time.

The short-term traffic flow prediction is of practical significance for the operation and management of the expressway. Combining the traffic flow data collected from the expressway network in Shandong Province, the short-term traffic flow prediction of expressway sections is studied to provide support for the establishment of vehicles travel path selection model. Firstly, the spatio-temporal correlation of traffic flow is analyzed and the correlation coefficients are calculated. Secondly, the summation autoregression and average long-term and short-term memory models based on time series, and regression prediction model based on spatial correlation are selected to predict the traffic flow at the section. Finally, the weighted least squares method is used for the spatio-temporal data integration prediction. The prediction results show that the prediction accuracy of the spatio-temporal traffic flow data fusion algorithm is higher than that of the single prediction model. The average absolute percentage error of the data fusion algorithm is reduced to 8.127%, and the average absolute error and root mean square error are lower than those of the single prediction model. The combined prediction model improves the prediction accuracy.

Nowadays, the construction of Internet of vehicles provides a lot of convenience for urban public safety and transportation. Among them, the prediction of traffic flow based on traffic road condition prediction is very important. Due to the interference of many external factors, such as unexpected events and weather, this problem is difficult. In recent years, due to its strong learning ability, deep learning has made many breakthroughs in various image classification and data analysis and processing problems. Among them, the traffic flow prediction method based on deep learning models can provide a set of rich tools, which can make good use of these data to build the Internet of vehicles. In this paper, we compare the deep learning model with the traditional model, and further attempt the preprocessing methods such as Wavelet and Singular Spectrum Analysis (SSA) to improve the performance of the deep learning model. Based on a real International Mobile Equipment Identity (IMEI) data set, we evaluated LSTM, GRU, ARIMA, SVR and ANN models. Considering the problem of whether the deep learning method is suitable for real-time traffic prediction, we counted and compared the training preprocessing time. We found that compared with LSTM and GRU, ARIMA is still competitive and Wavelet or SSA is not helpful as we expected.

The fundamental function of railway station is a tool for rapid passage of people and goods. The long-distance transportation function would be paid more attention by designers, neither than aesthetics and integration with cities. The Birmingham New Street Station had a long history since establishment. The railway station, in common with many other industrialized zone, has experienced major changes over the last 100 years. It went through 4 stages, which was mainly used for freight transportation initially. After that, it gradually turned to a comprehensive transportation hub. And finally Birmingham New Street Station developed into an urban space with people-oriented, convenient travel and commercial vitality. It is necessary and valuable to analyze the evolution and redevelopment of the railway station. This paper is aimed to summarize the development trend and optimization strategy of railway stations in central urban area and surrounding areas. It makes an in-depth study on the development history of Birmingham New Street Station, the type and site selection of station buildings, the commercial development mode of the station and its surrounding areas, and the connection organization between the station and urban traffic. Suggestion for the further development of railway stations in central cities could be proposed.

With the development of social economy, people's travel demands are more and more diversified, for travel with luggage users, the demand for luggage storage also tends to be more convenient methods. According to the survey, the existing luggage storage product design does not cover all the demands of travel users, its non-comprehensive development of the status quo is increasingly prominent. In this paper, for large pieces of luggage box, to luggage box storage related issues as the research direction, combined with the user demand inconvenience dilemma, joint Internet development under big data, artificial intelligence and cloud computing and other technologies, the luggage independent cloud hosting shared lock research.

Based on the baidu index data of Wuhan urban agglomeration (WUA) in 2014 and 2019, this paper uses social network analysis method to study the network characteristics of WUA from the aspects of connection intensity, connection types and cohesive subgroups. The results show that: (1) Compared with 2014, the overall information connection intensity of WUA has increased significantly in 2019, and regional differences have gradually eased, forming a complex network pattern with multiple axis distributions. (2) From 2014 to 2019, the number of marginal cities of regional information connection decreased. Wuhan has always been the central city for information connection. In 2019, Xianning and Ezhou are the leading cities, while Xiaogan and Huanggang are subordinate cities. (3) The four cities of Xiaogan, Xiantao, Tianmen, and Qianjiang in the western region are not closely connected. Xiantao became a subgroup independently in both years. Finally, it proposes a functional orientation suggestion of "one leader and multiple centers" with Wuhan as the leader, Xianning and Ezhou as the radiation centers, and Xiaogan and Huanggang as the undertaking centers.

Heterogeneous collaborative systems consisting of unmanned aerial vehicles/ground vehicles (UAV/UGV) have great potential for application in many fields. Among other things, UAV can provide a wide field of view and photography, while UGV can provide sufficient load capacity and act as relay stations. Rational planning of UAV/UGV paths based on actual tasks is an important issue to be addressed. This study proposes a hybrid unmanned system based on coordinated cooperation between UAV /UGV. In this system, the UGV is used as a mobile charging station to solve the UAV energy constraint problem. The UAV is used as a robotic system responsible for reaching the target point and solving the UGV functional constraint problem. We propose a path planning method for the study of two robots working together. A hierarchical path optimization strategy that combines classical and modern evolutionary methods. The method takes full advantage of the strengths of individual methods and algorithms in path selection and planning. Simulation results show that the collaborative UAV and UGV systems can improve the efficiency of performing tasks and that the hierarchical optimization strategy can improve the solution quality and stability of path planning.

The regional development of urban rail transit stations has gradually become an important fulcrum to drive the development of urban areas. On the basis of the traditional node-place theoretical model, the node-place evaluation indicator system of the station catchment area is constructed by using urban multi-source data, and the evaluation model is optimized by adding the "connection" evaluation dimension. Furthermore, the development of the station catchment area is evaluated with the coupling coordination degree model. Take the rapid development of Hangzhou Metro as the empirical object. The results show that the coupling coordination degree of the spatial development of the station catchment areas located in the center of the main city and the sub city is obviously better than that of the station catchment areas located at the edge of the urban area and the outer suburb. However, under the influence of the development strategy and traffic location, the coupling coordination degree of some stations is higher than that of the stations around it. Finally, it is helpful to provide the basis for the development strategy of station catchment areas under different location conditions.

It is of great practical significance to identify the state of bus bunching in advance so as to take reasonable measures. In order to improve the identification performance, a identification model based on Extreme Gradient Boosting (XGBoost) is proposed for multi classification of bus bunching rate. Firstly, using variance filtering and recursive feature elimination to screen the factors affecting the bus bunching rate. Secondly, SMOTE algorithm is used to deal with the data imbalance. Finally, XGBoost model is used to identify the multi classification of the bus bunching rate, and this paper compares the proposed model with other models. The research shows that the XGBoost model proposed in this paper has the best results in measurement indicators of identification performance, which verifies the applicability of the model to accurately identify the categories of bus bunching rate.

Garbage classification treatment is an indispensable part of national ecological civilization construction and its effective implementation is greatly affected by the efficiency of the urban domestic garbage collection system. In view of the vehicle routing optimization problem with vehicle capacity constraints and time window constraints, the genetic algorithm is used to solve and optimize the established model. The best collection and transportation paths of four kinds of urban domestic garbage are obtained, which significantly shortens the distance of collection and transportation paths. The effectiveness of the algorithm is verified, which provides ideas for improving the efficiency of urban domestic garbage classification, collection and transportation scheduling

The contemporary society is a fast developing, technologically advanced as well as information circulation society, people communicate more closely with each other and live more conveniently, and big data is the product of this high-tech era. The development of big data has given a strong impetus to urban planning and smart cities. Through the combination of big data technology and Internet of Things technology, modern people's lives are more closely integrated with the network, which improves people's work and life a lot. In today's world, big data technology has been applied to urban road traffic, social medical and urbanization management to achieve comprehensive management, which plays a very important role in the development of smart cities. This research focuses on the development direction of smart cities in the era of big data through the literature method. Combining the understanding of the literature and the actual development of Chinese cities, the research proposed a model of sustainable smart eco-city combined with renewable energy to provide reference for the development of smart eco-city.

Steel bridges have the advantages of light weight, high strength, prefabricated construction, and short construction time, and therefore have been widely used in many countries. In conventional bridge design, the load bearing capacity of the structure is considered as the most important safety factor. However, as the service life increases, the actual load-carrying capacity of bridges gradually decreases due to the combined action of the environmental corrosion and repeated vehicle loads, resulting in shortened bridge service life. In this paper, the fatigue reliability index of a steel girder bridge over its whole life is investigated based on artificial neural networks. The effects of truck traffic load and environmental corrosivity on the fatigue life of the steel girder bridge are analyzed and measures to control the traffic load are discussed. The research results can serve as a reference for traffic load management of highway steel bridges.

The environment in which the intelligent robot is dynamic in real time. The robot needs to respond to the surrounding obstacles in time to ensure that the robot can drive smoothly in an environment full of obstacles. This requires the robot to be intelligent enough to make decisions with different challenges. Obstacles in different directions and postures can be quickly identified and avoiding actions can be made smoothly. To solve this problem, this paper proposes an obstacle maze intelligent robot dynamic recognition and decision avoidance algorithm based on simulink simulation. By establishing a robot driving model, equipped with a radar sensor model, it has the ability to recognize obstacles, and uses the Stateflow tool to edit the robot obstacles. The object avoidance decision-making algorithm enables it to deal with obstacle avoidance in a variety of postures, and to explore the path out of the maze on its own. In order to verify the effectiveness of the model and algorithm, a maze of obstacle walls was built and the intelligent robot was simulated and tested. Through testing, the decision-making algorithm not only ensures the safety of the robot, but also achieves smooth obstacle avoidance and smoothly drove out of the obstacle wall maze.

With the rapid development of Chinese economy, the urban logistics distribution business has surged, and in order to approach the energy crisis and environmental pollution and other problems, China vigorously promotes the application of new energy vehicle industry, which makes the pure electric vehicles in the logistics field has been applied on a large scale, for the different distribution paths and different operation modes of electric logistics vehicles with quota charging method, the impact on the logistics distribution cost is different. In this paper, by analyzing the development status of electric logistics vehicles in China, combining the characteristics of electric logistics vehicles, and aiming at cost minimization, we establish an optimization model of urban distribution path of electric logistics vehicles based on quota charging method, and combine the constraints of quantity constraint, power constraint, load constraint, time window constraint, etc., to obtain and analyze the distribution scheme and distribution results of electric logistics vehicles under quota charging method, so as to provide logistics enterprises with the opportunity to It provides suggestions for logistics enterprises to reasonably plan distribution paths for electric logistics vehicles.

In the actual process of ship navigation, the sea state will change at any time according to the ocean climate. This change is uncertain. The conventional fin stabilizer control system often works poorly and the anti rolling effect cannot reach the ideal state due to engineering tuning, inaccurate parameter setting and other reasons. In this paper, genetic algorithm is used to optimize the three parameters of fin stabilizer PID control, so that the fin stabilizer control is always in the best working state, in order to achieve the desired effect of roll reduction.

In this paper, an evaluation method for the combined action of automatic emergency braking (AEB) and adaptive cruise control (ACC) was proposed. To evaluate the effectiveness of the test method, the test scenarios of “stationary vehicle in the curve” and “front car cut-in” were constructed. The tests were conducted on dry asphalt roads and the ISO 19206 standard was used as a vehicle target, and the combined effects of the AEB and ACC systems were carried out according to the test cases. By analyzing the test data such as speed, deceleration, relative speed to the front car, and relative longitudinal distance from the front car, the impact of ACC and AEB on occupant comfort and driving safety under the joint action of AEB and ACC was obtained.

With the development of autonomous driving technology, more and more attention is paid to the safety of autonomous driving system, such as functional safety, safety of intended functionality and cyber security. Among them, the safety of intended functionality refers to the safety problems caused by the insufficient function of automatic driving system and the harm caused by the misuse of personnel. System theory Analysis method (System Theoretic Process Analysis, STPA) is a kind of analysis method which treat the whole system as one object. In this paper, STPA analysis method is applied to adaptive cruise control (ACC) system, the control schematic of ACC system is constructed, the unsafe control behavior of the system is analyzed, and the system constraints and typical test scenarios are obtained. Taking the front vehicle cutting in scenario as an example, through using autonomous robots and navigable target vehicle, the obstacle avoidance ability of the driver for the front vehicle cutting in scenario with different speeds at 120km/h is tested. When the preceding vehicle cutting in speed is 60km/h, the collision can be avoided whereas the cutting distance is 31.8m or above. When the preceding vehicle cuts in at the speed of 80km/h, the collision can be avoided whereas the cutting distance is 16.7m or above. This index can be used as the requirements for ACC system in the cut-in scenario. In this paper, the ACC system is analyzed in detail for the safety of intended functionality and relevant requirements are given. The whole method and steps are also applicable to other automatic driving systems.

"Medium and Long Term Railway Network Planning" describes the grand blueprint of "eight vertical and eight horizontal" high-speed railway network, marking that China has officially entered the heyday of high-speed railway construction. At present, China is in a leading position in the development of high-speed railway in the world. This research selects China’s high-speed railway transport network from 2014 to 2020 as the research object, high-speed railway stations as network nodes, the ratio of passenger flow to running time as the edge weight, and builds a weighted undirected network diagram. Gephi is used to visualize the high-speed railway transport network. Finally, the spatio-temporal variation rules of China’s high-speed railway transport network are explored from two aspects of nodes and the whole network. It is found that the difference of different node degrees will gradually change from large in the early stage to small in 2020. Small world features are becoming more and more prominent, and network performance is improving. China’s high-speed rail network was initially developed mainly in the economically developed central and eastern regions, but has gradually shifted to the western region since 2017. China’s high-speed rail transport network has shifted from economically developed, densely populated areas to underdeveloped, sparsely populated areas with transportation demands.

The UAV flight plan should comprehensively consider the influence of factors such as the slope environment, slope safety level, geological conditions, and UAV flying conditions. The +360 sections of the slope are graded for safety, and the technical safety index of the slope is finally assessed as Class three, so as to determine the fine inspection plan. The slope was carefully inspected by drone inspection equipment, and the development of the disease on the surface of the slope can be clearly seen. Among them, there is a rock exposed at point three and there is a risk of slipping, which should be focused on in the follow-up inspection. focus on. Points four, five, six and eight are weathered rocks, and the surface has been partially peeled off, there is a risk of continued peeling, which should be paid attention to in the follow-up inspection work. It brings convenience to the inspection of highway slopes and has a wide application prospect.

With the rapid development of the world economy, the number and scale of road transportation infrastructure have grown rapidly. In recent years, a large number of highway tunnels have been put into use. The prevalence of water seepage diseases in road tunnels poses a major hazard to the safety of personnel and vehicles. Water seepage detection has been one of the high-priority research topics for tunnel inspection. Previous studies have mainly used a single visible camera as a sensor to detect water leakage areas in images, which is extremely sensitive to insufficient lighting in the tunnel. Considering the existence of temperature difference between the water leakage area and the normal area, we used an infrared camera to collect tunnel lining images and constructed a water leakage area identification algorithm based on the temperature difference between the water leakage area and the normal area using K-means clustering algorithm and low-pass filtering algorithm based on the temperature field distribution of infrared images. This study can provide a new idea for the rapid identification of tunnel water leakage.

In order to investigate the fire smoke diffusion and migration characteristics of super large cross-section urban tunnel, a 1/15 scaled tunnel model was established based on Xintang interchange with covered, and experiments were carried out under the longitudinal smoke exhaust mode. The morphological characteristics of the smoke layer and the smoke temperature distribution in the tunnel under different longitudinal air velocity under the longitudinal smoke exhaust mode are obtained, the critical air velocity of the actual project is determined. Results indicated that, during the initial stage of fire in large cross-section road tunnel, the fire scale and air velocity are important factors, which affect the temperature field and smoke diffusion. The hot smoke from the fire in tunnel tends to diffuse to the vault. Therefore, the high temperature region occupied the upper space of the tunnel, while the temperature of lower part was lower. Larger inner space of large cross-section road tunnel is conductive for fire smoke spreading. The longitudinal smoke exhaust wind velocity that controls the smoke not to produce countercurrent is about 3.0 m/s. Due to the elimination of the diaphragm in the same direction, the heat generated by the fire source has an impact on the downstream of the adjacent ramp. The temperature in the downstream area of adjacent ramps increased, which is lower than 30 ℃.

The stability of the elevation control network is the key to ensuring the correct construction of urban rail transit projects according to the design scheme. Due to the long construction period of urban rail transit projects, the ground elevation control network is vulnerable to instability and destruction caused by urban development and its engineering construction. Regular repetition surveys are required to ensure accuracy and stability. In addition, when the external environment changes suddenly, it is necessary to encrypt and retest the elevation control network in time, such as the potential impact of Zhengzhou 7-20 rainstorm on ground elevation control points. To clarify the changing trend and potential reasons of the subway elevation network, this study takes the elevation control network of Zhengzhou Metro Line 8 as an example. This paper first introduces the layout method, repetition survey principle, technical measurement requirements, and the stability analysis method of the starting point and results update standard. Secondly, the potential causes of the change of the subway elevation control network caused by rainstorms and the influence of regional settlement on the subway elevation control network are preliminarily analyzed by using the extra repetition survey results and conventional repetition survey results. Finally, the solution to the influence of regional settlement on the subway is proposed. The results show that: 1. Using the method of combined elevation difference can judge whether the starting point is stable; 2. ±5mm as the result update margin is reasonable; 3. It is appropriate to adopt the countermeasures of “ensure an error is controllable in the process and one-time adjustment after interval penetration” in the construction of the subway, and it is an effective means to control the influence of settlement for the operation of subway to control the surrounding groundwater exploitation.

In China, the smart transportation project mode is top-down, dominated by the government, participated by enterprises, and used by the public. The behavior strategy choice of different stakeholders will affect the process and effect of the smart transportation project. This paper takes the stakeholders of intelligent transportation as the research object, analyzes the game under different behavior strategies from the two stages of construction and operation, and finds out the best behavior for all parties of the project, to ensure smooth progress and effect of the intelligent transportation project.

With the formation of a general consumerist leisure culture in society, inland river tourism provides a good choice to meet the needs of post-modern tourists seeking unique manifestations. As the carrier of this kind of tourism, tourism ships are the primary prerequisite and important guarantee for the safety. Starting from the safety monitoring of inland river tourism ship equipment and navigation, this paper studies and puts forward the top-level design of the intelligent safety real-time monitoring technology framework of inland river tourism ship. The real-time monitoring of shipboard, the data transmission and synchronization strategy of ship and shore, and the frame structure of shore monitoring are designed in detail. Based on intelligent real-time monitoring of equipment failures and navigation safety risks of inland river tourism ships, it can effectively ensure the navigation safety and reduce navigation accidents.

With the continuous expansion of the scale of modern urban construction and the wide application of information technology in architectural design, the level of intelligence and informatization in urban construction has been significantly improved. Among them, the application of BIM technology in smart city construction has not only changed traditional buildings. At the same time, it also effectively improves the efficiency of modern smart city construction and makes architectural design more scientific. Moreover, smart city construction is the integration of modern science and technology with traditional architectural design. Under the circumstance of emphasizing the structure, space, layout and function of traditional architectural design, the traditional architectural design scheme can be effectively implemented through BIM technology, which has an important role in promoting the construction of smart city.

Under the influence of the fifth industrial revolution and the outbreak of COVID-19, the digital transformation of enterprises has entered a new stage of rapid development. Digital transformation has become the trend of enterprise operation in the digital economy era. In this context, enterprise laboratory asset operation has also become an important aspect of enterprise digital operation. It is urgent to build a set of enterprise laboratory asset digital evaluation system to assist the implementation of enterprise digital strategy. Based on the characteristics of laboratory assets and the closed-loop theory of asset operation management, this paper analyzes and studies the laboratory asset management, establishes a targeted evaluation index system of digital asset management, focuses on the composition of the digital operation system of laboratory assets, and constructs a management index evaluation system of assets, efficiency, cost and other dimensions, so as to create a real-time, comprehensive and comprehensive evaluation system The closed-loop and full cycle digital management ecological environment realizes the effective integration of laboratory resource fragmentation information and the complete embodiment of digitization, provides service support for continuously improving asset management performance, and provides support for further improving enterprise economic efficiency and operation level.

In the process of intelligent driving simulation test, the vehicle dynamics model has a certain impact on the simulation results. In order to study how to calibrate the parameters of vehicle dynamics model based on intelligent driving simulation test, the vehicle dynamics model is built based on Carmaker dynamics software platform and real vehicle data. Select the typical test conditions, one is the test conditions for the longitudinal characteristics of the vehicle; The other is the test condition for vehicle lateral characteristics. Through the benchmarking analysis between the simulation analysis results and the field test results of the real vehicle, we can evaluate whether the longitudinal and transverse performance of the built dynamic model meets the requirements of intelligent driving simulation.